Understand an IT error code
Search for a code, message, or domain to understand what it means, likely causes, and the first checks to perform.
0x80004005
Error not specified
Generic code used when a component does not provide a more precise cause.
View causes and solutions →0x80042306
VSS provider veto
A VSS provider refused or blocked snapshot creation.
View causes and solutions →0x8004230F
VSS unexpected provider error
VSS received an unexpected error from a snapshot provider.
View causes and solutions →0x80042318
VSS writer not responding
A required VSS writer is not responding correctly.
View causes and solutions →0x8004231F
VSS insufficient storage
The storage available for VSS shadow copies is insufficient.
View causes and solutions →0x80070002
File not found
Windows does not find a required file, often during an update, installation or backup.
View causes and solutions →0x80070003
Path not found
The path to a local or network resource does not exist or is not properly resolved.
View causes and solutions →0x80070005
Access denied
Windows or an application does not have the rights to read, write or modify a resource.
View causes and solutions →0x80070020
File in use by another process
A file or resource is locked by another process at the time of the operation.
View causes and solutions →0x80070035
Network path not found
Windows cannot reach a UNC path or an expected SMB resource.
View causes and solutions →0x80070043
Network name not found
The server may be reachable, but the required share or resource name does not exist.
View causes and solutions →0x80070070
Insufficient disk space
The target volume does not have enough free space to complete the operation.
View causes and solutions →0x80070422
Service disabled
The service required for the operation is disabled or cannot be started.
View causes and solutions →0x80070424
The specified service does not exist
Windows does not find the service expected by the operation.
View causes and solutions →0x8007052E
Logon failure
The supplied username or password was not accepted by the system or remote resource.
View causes and solutions →0x800705B4
The operation timed out
A Windows operation did not complete before the deadline.
View causes and solutions →0x80070643
Fatal error during installation
Windows Installer or an installation package failed before completing the deployment.
View causes and solutions →0x800706BA
The RPC server is unavailable
Windows cannot reach the RPC service required for the requested operation.
View causes and solutions →0x80072EE2
The operation timed out
An HTTP/HTTPS connection expected by Windows did not respond within the time frame.
View causes and solutions →0x80072F8F
Secure connection validation failure
Windows does not properly establish or validate a secure TLS connection.
View causes and solutions →0x80072F8F
TLS security or date error
A secure connection fails, often due to the clock, certificate or TLS.
View causes and solutions →0x80073712
Corrupt Windows components
Files required for Windows Update are missing or damaged.
View causes and solutions →0x80073712
Damaged component store
Windows detects components necessary for updates or maintenance as missing or corrupt.
View causes and solutions →0x8009030C
Logon denied
SSPI refuses the authentication with the available information.
View causes and solutions →0x8009030E
No credentials are available
The security component does not have the information necessary to authenticate the session.
View causes and solutions →0x80090322
Incorrect target principal name
The expected Kerberos identity does not match the targeted service.
View causes and solutions →0x80090322
The target principal name is incorrect
Kerberos negotiation cannot properly validate the target service, often because of a SPN or,an inconsistent DNS name.
View causes and solutions →0x800B0109
Certificate chain terminates in an untrusted root
The certificate submitted goes back to a root authority which is not approved by the system.
View causes and solutions →0x800F081F
Source files could not be found
DISM or Windows Update does not find the files needed to repair or install a Windows component.
View causes and solutions →0x800F0831
Missing package or dependency
Windows does not find a package required to complete the installation.
View causes and solutions →0x800F0906
Could not download source files
DISM fails to recover the components necessary for repair.
View causes and solutions →0x800F0922
Update installation failure
A Windows update could not complete its installation; several causes are possible.
View causes and solutions →0x800F0922
Windows Update installation failed
Windows update or functionality cannot be installed.
View causes and solutions →0x80240034
Windows Update download failed
Downloading a Windows update is not ending correctly.
View causes and solutions →0x8024401C
Windows Update timeout
Windows Update client exceeds a delay when communicating with the service.
View causes and solutions →0x8024402C
Windows Update proxy/DNS error
Windows Update is not able to properly resolve or join its update service.
View causes and solutions →0xc0000005
0xC0000005 — Access violation
An application has tried to access a closed memory area.
View causes and solutions →0xC1900101
Driver-related upgrade failure
A Windows upgrade failed, most commonly because of a driver or hardware device.
View causes and solutions →401
Unauthorised
The resource requires valid authentication.
View causes and solutions →403
No access
The server understands the request but refuses access.
View causes and solutions →404
Page not found
The requested resource does not exist at the specified address.
View causes and solutions →408
SIP request timeout
The SIP request did not receive a final response within the expected time.
View causes and solutions →409
Conflict
The request is valid but conflicts with the current state of the resource.
View causes and solutions →410
Resource permanently removed
The server indicates that the resource used to exist but is permanently unavailable.
View causes and solutions →412
Precondition failed
A condition sent in the request headers is not satisfied.
View causes and solutions →416
Requested range not satisfiable
The client requested a byte range that does not exist in the resource.
View causes and solutions →423
Resource locked
The resource is locked and cannot currently be modified.
View causes and solutions →426
Protocol upgrade required
The server requires the client to use a different protocol or version.
View causes and solutions →480
Destination temporarily unavailable
The SIP endpoint or service is temporarily unavailable.
View causes and solutions →486
Busy here
The called endpoint reports that it is busy and cannot accept the call.
View causes and solutions →487
SIP request terminated
The SIP transaction was canceled, often after a CANCEL request.
View causes and solutions →488
Media or SIP parameters not acceptable
The destination rejects the offered parameters, often codecs or SDP.
View causes and solutions →500
Internal server error
An unexpected error prevents the server from processing the request.
View causes and solutions →503
Service unavailable
The service is temporarily unavailable or overloaded.
View causes and solutions →503
SIP service unavailable
The SIP server or trunk is temporarily unable to process the request.
View causes and solutions →507
Insufficient storage
The server lacks enough storage to complete the operation.
View causes and solutions →508
Loop detected
The server detected an infinite loop while processing the request.
View causes and solutions →520
Origin web server returned an unknown error
Cloudflare received an empty, unexpected, or unparseable response from the origin server.
View causes and solutions →521
Origin web server is down
Cloudflare cannot establish a connection to the origin web server.
View causes and solutions →522
Connection to origin timed out
The TCP connection to the origin does not respond within the expected timeout.
View causes and solutions →523
Origin is unreachable
Cloudflare cannot reach the IP address configured for the origin.
View causes and solutions →524
Origin processing timeout
Cloudflare connected successfully but the origin did not return a response quickly enough.
View causes and solutions →535 5.7.139
SMTP AUTH deactivated
Microsoft 365 refuses the SMTP authentication of the client because SMTP AUTH is disabled to the required level.
View causes and solutions →535 5.7.3
SMTP authentication failure
The server refuses the, ID, password or method of authentication.
View causes and solutions →550 5.1.1
Unknown recipient
The server has no name on the recipient's address.
View causes and solutions →550 5.7.1
550.57.1 — Sender mismatch
address of sender is not the authenticated account or is not authorized to send.
View causes and solutions →550 5.7.1
55057.1 — Unauthorised shipment
The SMTP server refuses the message for a reason of authorization, relay or policy.
View causes and solutions →554 5.7.1
Message rejected as spam
The recipient server considers the message or the sender as undesirable.
View causes and solutions →603
SIP call declined
The destination explicitly declines the call and indicates no alternate branch should be tried.
View causes and solutions →AADSTS50011
Reply URL mismatch
The redirect URI sent by the application does not match a registered redirect URI.
View causes and solutions →AADSTS50076
Multi-factor authentication required
Microsoft Entra ID requires multi-factor authentication to continue sign-in.
View causes and solutions →AADSTS53003
Access blocked by Conditional Access
The sign-in is blocked by a Conditional Access policy.
View causes and solutions →AADSTS700016
Application not found in tenant
The requested application identifier does not exist or is not available in the target tenant.
View causes and solutions →AUTH_FAILED
VPN authentication refused
The VPN server refuses the user, certificate or second factor.
View causes and solutions →Établissement de connexion BDD
BDD Connection Facility — Error when establishing the connection to the database
WordPress no longer manages to connect to MySQL or MariaDB.
View causes and solutions →Ceph
HEALTH_ERR
Ceph reports a critical state requiring analysis of OSD, PG, capability or monitors.
View causes and solutions →Cloudflare 525
SSLhandshakeDownload
The proxy Cloudflare does not manage to properly set up the TLS session with the original server.
View causes and solutions →Cloudflare 526
STST SSL-1999
Cloudflare considers the certificate of the server of which is invalid in strict mode.
View causes and solutions →Erreur critique
Critical error — A critical error occurred on this site
WordPress encountered a fatal PHP error.
View causes and solutions →cURL 28
Operation timed out
A URL request did not finish before the set time.
View causes and solutions →cURL 60
SSL certificate problem
cURL fails to properly validate the target's TLS certificate.
View causes and solutions →DFSR Event ID 2213
Replication interrupted after unexpected stop
DFSR suspended replication of a volume after an unclean shutdown.
View causes and solutions →DNS Event ID 4004
DNS integrated with AD
The DNS server was unable to perform a necessary Active Directory operation.
View causes and solutions →DNS Event ID 4013
DNS is waiting for Active Directory synchronization
The DNS service integrated with AD waits for initial synchronization before loading certain areas.
View causes and solutions →DNS NXDOMAIN
No-existent domain name
The DNS server indicates that the name requested does not exist in the solved area.
View causes and solutions →Event ID 1000
Application
An application or module caused an error in execution.
View causes and solutions →Event ID 1001
Windows Error Reporting
Windows Error Reporting recorded a report after a crash or an application incident.
View causes and solutions →Event ID 10016
DistributedCOM permission
A COM/DCOM application tried a "Migration" without the expected authorization.
View causes and solutions →Event ID 1014
DNS Client timeout
Windows DNS client does not get a response within the time frame.
View causes and solutions →Event ID 10154
DNS registration failure
Windows did not manage to dynamically record its DNS records.
View causes and solutions →Event ID 1030
Group Policy processing failure
The treatment of group strategies could not be completed correctly.
View causes and solutions →Event ID 1058
GPO readout failure
Windows could not read a group strategy from SysVOL or an associated path.
View causes and solutions →Event ID 11
Controller error
A controller error is detected on the I/O path.
View causes and solutions →Event ID 1129
Group Policy failure due to lack of domain connectivity
Windows could not apply strategies because connectivity with a domain controller was not available.
View causes and solutions →Event ID 12289
VSS snapshot error
VSS reported an error while creating or managing a snapshot.
View causes and solutions →Event ID 129
Reset to device issued
The storage driver re-opted a device after a timeout.
View causes and solutions →Event ID 1311
Problem of AD replication topology
The Knowledge Consistency Checker does not find a satisfactory replication path.
View causes and solutions →Event ID 153
Disk I/O retried
Windows must have retryed an operation of input/output on a disk.
View causes and solutions →Event ID 157
Disk surprise removed
Windows considers that a disk has been removed unexpectedly.
View causes and solutions →Event ID 1865
Unable to form the replication topology
Active Directory cannot properly build the necessary replication connections.
View causes and solutions →Event ID 2019
Insufficient unpaginated memory
The system no longer has sufficient unpaginated memory to satisfy an allocation.
View causes and solutions →Event ID 2020
Insufficient pagina memory
The system has experienced a shortage of resources in the paginated pool.
View causes and solutions →Event ID 2042
Too old replication
A domain controller has been out of replication for too long and AD blocks replication to avoid persistent objects.
View causes and solutions →Event ID 2087
DNS resolution failure of an AD partner
A domain controller does not properly resolve a replication partner.
View causes and solutions →Event ID 2103
Active Directory database restored incompatibly
Active Directory detects a baseline state that can lead to a USN rollback.
View causes and solutions →Event ID 2212
DFSRRek
DFSR performs recovery after a volume shutdown or incident.
View causes and solutions →Event ID 36874
Schannel handshake failure
S Channel was unable to negotiate a TLS connection correctly.
View causes and solutions →Event ID 36887
Schannel fatal alert received
The TLS pair sent a fatal alert to the S Channel component.
View causes and solutions →Event ID 36888
Schannel fatal alert
S Channel generated or received a fatal TLS alert.
View causes and solutions →Event ID 40960
LSA / secure authentication
LSA reports a negotiation or d problem, authentication with a Service Service.
View causes and solutions →Event ID 40961
LSA/87 package
Windows reports a failure of authentication via a security package.
View causes and solutions →Event ID 41
Kernel-Power
Windows restarted without stopping clean detected.
View causes and solutions →Event ID 4625
Log-in failed
Windows recorded an attempt of authentication failed.
View causes and solutions →Event ID 4740
Locked user account
Active Directory locked an account after repeated authentication failures.
View causes and solutions →Event ID 4768
Request by TGT Kerberos
A domain controller processed an application for Ticket Air Ticket.
View causes and solutions →Event ID 4769
Request for Kerberos service ticket
A Kerberos service ticket has been requested for a SPN.
View causes and solutions →Event ID 4771
Kerberos pre-authentication failure
Kerberos refused pre-authentication for an account.
View causes and solutions →Event ID 50
Delayed Write Failed
Windows could not write cached data on storage.
View causes and solutions →Event ID 5002
1990 application pool1999
IIS/WAS disabled a pool after several quick failures.
View causes and solutions →Event ID 55
NTFS corruption
NTFS detects a file system inconsistency.
View causes and solutions →Event ID 5719
No domain controller available
Netlogon was unable to establish a secure channel with a domain controller.
View causes and solutions →Event ID 5722
Invalid machine account password
The secure channel of a computer with the domain is probably unsynchronized.
View causes and solutions →Event ID 5805
Session 2008 from Computerdown
A domain controller refuses the trust relationship of a computer account.
View causes and solutions →Event ID 6008
Unexpected system shutdown
Windows reports that a previous stop was not performed correctly.
View causes and solutions →Event ID 7
Bad block
The system reports a defective block on a storage device.
View causes and solutions →Event ID 7000
Service failed to start
Service Control Manager couldn't start a service.
View causes and solutions →Event ID 7001
Service dependency failed
A service did not start because an addiction was unavailable.
View causes and solutions →Event ID 7009
Service start timeout
A service did not respond quickly enough during its start.
View causes and solutions →Event ID 7011
Service control timeout
A service did not respond to an order from the Service Control Manager within the time frame.
View causes and solutions →Event ID 7031
Service ended unexpectedly
The Service Control Manager says a service stopped abruptly.
View causes and solutions →Event ID 8193
VSS error
VSS logged an error during a snapshot or writer operation.
View causes and solutions →Event ID 8193
VSS error during an operation
The Volume Shadow Copy service encounters an error during preparation or execution of a photograph.
View causes and solutions →Event ID 98
NTFS volume requires offline scan
NTFS indicates that offline repair may be required.
View causes and solutions →HTTP 400
Bad Request
The server considers the request invalid.
View causes and solutions →HTTP 401
An Authorized
The resource requires a valid authentication that has not been, provided or accepted.
View causes and solutions →HTTP 403
Forbidden
The server understands the request but refuses access to the resource.
View causes and solutions →HTTP 405
Method Not Keyed
The HTTP method used is not allowed for this resource.
View causes and solutions →HTTP 408
Timeout
The server expired pending the client's request.
View causes and solutions →HTTP 413
PayloadTM Wide
The size of the request body exceeds the accepted limit.
View causes and solutions →HTTP 415
A Thousands Media Type
The server refuses the type of content sent.
View causes and solutions →HTTP 422
A Processable Content
The request is valid only but fails to validate the business.
View causes and solutions →HTTP 429
TM Myces
The client exceeded a limit of requests imposed by the service.
View causes and solutions →HTTP 431
Request Header Fields - Large
Query headers exceed a server or proxy limit.
View causes and solutions →HTTP 502
Bad Gateway
A proxy or gateway received an invalid response from the upstream application server.
View causes and solutions →HTTP 503
Service A Point
The web server or the application indicates that the service is temporarily unavailable.
View causes and solutions →HTTP 504
19 Timeout
A gateway did not receive a response from the server upstream within the set time.
View causes and solutions →Hyper-V
The chain of virtual hard disks is corrupted
The VHDX or AVHDX chain of a virtual machine n is more coherent.
View causes and solutions →Hyper-V
Virtual machine failed to start
Hyper-V cannot start a virtual machine.
View causes and solutions →IKE timeout
Ex IKE negotiation
The Channel is not responding correctly to IPsec negotiation.
View causes and solutions →Linux
No spaceleft on device
The kernel or application can no longer write to the target filesystem.
View causes and solutions →MySQL 1045
Access denied for user
MySQL or MariaDB refuses the authentication of, user.
View causes and solutions →MySQL 1205
Lock wait timeout exceeded
One transaction is waiting too long for a lock held by another transaction.
View causes and solutions →MySQL 1213
Deadlock found
Transactions are blocking each other and one has to be cancelled.
View causes and solutions →MySQL 2002
Can't connect to local server
The client cannot reach the local MySQL server.
View causes and solutions →NO_PROPOSAL_CHOSEN
No IP-proposals in the IP sector
The cryptographic parameters of the two IP-ends in the year 1995 do not match.
View causes and solutions →PHP
KeyedImport size
PHP reached its memory limit during execution.
View causes and solutions →PHP
Maximum execution time exceeded
A PHP script exceeds the maximum duration of run.
View causes and solutions →PHP
Too many input variables
PHP ignores some of the fields when max_input_vars is exceeded.
View causes and solutions →Proxmox
Cluster not ready — no quorum
The Proxmox Cluster no longer has the quorum required for certain operations.
View causes and solutions →Boucle de redirection
Redirecting loop — ERR_TOO_MANY_rejects
The browser is rerouted to a loop between multiple URLs….
View causes and solutions →Repository unavailable
Backup repository unavailable
The backup software can no longer join or write in the repository…
View causes and solutions →DNS SERVFAIL
SERVFAIL DNS — DNS server failed
The DNS solver was unable to provide a valid response to the request.
View causes and solutions →SMTP 421 4.4.2
Stopped SMTP connection
The SMTP server temporarily closes the connection or cannot continue the session.
View causes and solutions →SMTP 450 4.2.0
MailboxOceania
The recipient is temporarily unavailable.
View causes and solutions →SMTP 451 4.4.62
Microsoft 365 temporary routing error
Exchange Online returns a temporary error related to routing or transfer.
View causes and solutions →SMTP 451 4.7.500
Temporary processing error
The server asks to try again later, often because of a protection or,a temporary limitation.
View causes and solutions →SMTP 452 4.2.2
______________ storage / temporary quota
The server cannot accept the message due to lack of resources or quota.
View causes and solutions →SMTP 535 5.7.3
Authentication unsuccessful
SMTP server refuses identifiers or method of authentication.
View causes and solutions →SMTP 550 5.1.1
Recipient address rejected
The recipient address does not exist or is not recognized by the remote mail domain.
View causes and solutions →SMTP 550 5.4.1
9/ 9: access
The server refuses routing or access to the recipient.
View causes and solutions →SMTP 550 5.7.26
Unauthenti(5 ) email
The message is rejected because the authentication of the sender domain is insufficient according to the policy of the recipient.
View causes and solutions →SMTP 550 5.7.60
Send As denied
The authenticated account does not, have the right to, send with the, From address used.
View causes and solutions →SMTP 550 5.7.64
Relay / tenant attribution denied
Exchange Online refuses the message because the stream is not correctly assigned or allowed.
View causes and solutions →SMTP 550 5.7.705
Tenant exceeded threshold
Microsoft 365 limits the sending after exceeding,a threshold or abnormal behavior.
View causes and solutions →SMTP 550 5.7.708
Traffic not accepted
Exchange Online blocks a stream due to a policy, reputation or protection measure.
View causes and solutions →SMTP 552 5.2.2
Exceeded box quota
The recipient's box or storage cannot accept the message anymore.
View causes and solutions →SMTP 554 5.7.1
SMTP 554.57.1 — Rejected message for policy or security
The server has finally refused the message for a security or policy rule.
View causes and solutions →Snapshot chain invalid
Inconsistent snapshot chain
A virtual disk or backup depends on a missing or invalid parent in the snapshot chain.
View causes and solutions →systemd
Start request repeated too quickly
systemd stopped restarting a service after several rapid failures.
View causes and solutions →VMware
File nd not found
A VM or VMware task refers to a file that is no longer present at the expected location.
View causes and solutions →VMware
SK disk space on data store
The data store no longer has sufficient space for the requested operation.
View causes and solutions →VSS 8194
VSS access error
VSS encountered an error, often related to permissions or the,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
View causes and solutions →VSS_E_WRITERERROR_TIMEOUT
VSS writer timeout
A required VSS writer did not complete its operation within the allowed time.
View causes and solutions →Écran blanc
White Screen — White Screen of Death
WordPress displays an empty page, usually following a PHP error.
View causes and solutions →WordPress
Error establishing a database connection
WordPress does not manage to connect to its database.
View causes and solutions →WordPress
The site is experiencing technical difficulties
WordPress detects a fatal error and displays a recovery page.
View causes and solutions →These pages are diagnostic aids. Back up data and assess the impact before changing a production system.