Error map
18456 SQL Server: Login failed for user 'x'. (Error 18456)
SQL · layer 5, Data
Centre: this error. First ring: errors it is linked with (11). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (11)
MySQL ERROR 1045 (28000): Access denied for user
MySQL rejected the login — wrong password, wrong user/host combination, or the user doesn’t exist.
MySQL ERROR 1698 (28000): Access denied for user 'root'@'localhost'
root uses the auth_socket/unix_socket plugin (Ubuntu/Debian default), so password logins as root fail.
ORA-01017: invalid username/password; logon denied
Oracle rejected the credentials.
PostgreSQL: FATAL: password authentication failed for user
PostgreSQL rejected the password for that role, or pg_hba.conf requires a different auth method.
SQL Server: Arithmetic overflow error converting expression to data type int. (Msg 8115)
A value or calculation exceeds the target data type’s range.
SQL Server: Cannot insert explicit value for identity column in table 'x' when IDENTITY_INSERT is set to OFF.
An INSERT supplied a value for an IDENTITY column.
Azure SQL: Cannot open server 'x' requested by the login. Client with IP address 'y' is not allowed to access the server (Error 40615)
The Azure SQL server firewall doesn’t allow your client’s IP address.
SQL Server: Conversion failed when converting the varchar value 'x' to data type int. (Msg 245)
SQL Server tried to convert text to a number (often implicitly) and hit a non-numeric value.
SQL Server: Execution Timeout Expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
The command ran longer than the client’s CommandTimeout (default 30 seconds).
FATAL: role "x" does not exist
PostgreSQL has no login role with that name.
SQL Server: The certificate chain was issued by an authority that is not trusted.
The client requires an encrypted connection and doesn’t trust SQL Server’s (often self-signed) certificate.
Two steps away (29)
MySQL ERROR 1044 (42000): Access denied for user to database
The login succeeded, but the user has no privileges on the database you’re using.
MySQL ERROR 2002 (HY000): Can't connect to local MySQL server through socket
The client couldn’t reach the MySQL server — it isn’t running, or the client is looking for the socket/port in the wrong place.
MySQL ERROR 2006 (HY000): MySQL server has gone away
The connection to MySQL was closed — usually by a timeout or a packet larger than `max_allowed_packet`.
MySQL ERROR 1130 (HY000): Host 'x' is not allowed to connect to this MySQL server
No MySQL account exists for the host you’re connecting from.
Authentication plugin 'caching_sha2_password' cannot be loaded
An old MySQL client/driver can’t use MySQL 8’s default authentication plugin.
ORA-00942: table or view does not exist
Oracle can’t see the table — it doesn’t exist, is in another schema, or you lack privileges on it.
ORA-00904: "X": invalid identifier
A column name in the statement doesn’t exist (or is misquoted).
ORA-00001: unique constraint (SCHEMA.PK_X) violated
An insert/update duplicated a value in a unique or primary key constraint.
PostgreSQL: ERROR: relation "x" does not exist
The table/view isn’t found — missing migration, wrong schema, or a case-sensitive quoted name.
PostgreSQL: could not connect to server / connection refused — Is the server running on host and accepting TCP/IP connections?
The client reached no PostgreSQL listener at that host/port — the server is down, listening elsewhere, or not accepting remote co…
PostgreSQL: ERROR: permission denied for table / schema public
The role is connected but lacks privileges on that table or schema — very common after PostgreSQL 15 removed CREATE on the public…
ERROR: numeric field overflow — A field with precision 5, scale 2 must round to an absolute value less than 10^3
A number doesn’t fit the column’s numeric(precision, scale) or integer range.
SQL Server: Invalid object name 'x'. (Msg 208)
The table/view doesn’t exist in the current database or schema.
SQL Server: Invalid column name 'x'. (Msg 207)
SQL Server can’t find the column — typo, missing migration, or a string in double quotes with QUOTED_IDENTIFIER ON.
SQL Server: Violation of PRIMARY KEY constraint 'x'. Cannot insert duplicate key in object 'y'. (Msg 2627)
An insert duplicated a primary key or unique constraint value.
SQL Server: String or binary data would be truncated in table 'x', column 'y'. (Msg 2628)
A value is longer than the column allows.
SQL Server: A network-related or instance-specific error occurred while establishing a connection to SQL Server. (provider: Named Pipes Provider, error: 40 / TCP Provider, error: 26)
The client couldn’t reach the SQL Server instance — wrong server name/instance, TCP disabled, firewall, or SQL Browser not runnin…
Cloudflare Error 1020: Access Denied
A Cloudflare firewall/WAF custom rule blocked the request — the visitor’s IP, country, user agent or request pattern matched a bl…
driver failed programming external connectivity on endpoint: iptables: No chain/target/match by that name
Docker’s iptables rules were wiped (firewalld/ufw reload, iptables flush) while Docker was running, so it can’t publish ports.
ssh: connect to host x port 22: Connection timed out
SSH packets get no reply — a firewall/security group drops them, the server is off, or the IP is wrong.
ERROR: invalid input syntax for type integer: "abc"
A string couldn’t be converted to the column’s type (integer, numeric, boolean, date…).
SQL Server: The INSERT statement conflicted with the FOREIGN KEY constraint 'x'. (Msg 547)
The row references a parent that doesn’t exist (or a DELETE would orphan children).
SQL Server: Incorrect syntax near 'x'. (Msg 102)
T-SQL couldn’t parse the statement near the shown token.
Lock wait timeout exceeded; try restarting transaction (MySQL 1205)
A query waited too long for a row lock held by another transaction and gave up.
ERROR: canceling statement due to statement timeout
A query ran longer than statement_timeout and PostgreSQL cancelled it.
API Gateway: {"message": "Endpoint request timed out"} (504 after 29 seconds)
The backend (usually Lambda) didn’t respond within API Gateway’s integration timeout (29 seconds by default for REST APIs).
SSL: CERTIFICATE_VERIFY_FAILED / unable to get local issuer certificate
The client couldn’t verify the server’s TLS certificate chain, so it refused the HTTPS connection.
SSL error: tlsv1 alert protocol version / unsupported protocol / no protocols available
The client and server couldn’t agree on a TLS version or cipher, so the HTTPS handshake failed before any HTTP was exchanged.
ACM certificate stuck in Pending validation
ACM is waiting to see the DNS (or email) validation record — it wasn’t created, was created in the wrong DNS zone, or has a typo.
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