HL ErrorCodes
Error Codes
Error codes in the Hotline protocol are 4-byte (32-bit) integers. A value of 0 always indicates "No Error" (Success).
General Errors
These are commonly returned in the Transaction Header during basic operations.
| Code (Dec) | Constant | Description |
|---|---|---|
| 0 | err_None | Success / No Error. |
| -1 | err_Generic | A non-specific error occurred. |
| 1 | err_NotConnected | The operation requires a connection that is no longer active. |
| 2 | err_Socket | A low-level TCP/IP socket error occurred. |
Login & Access Errors
These typically occur during Transaction 107 (Login) or when trying to perform restricted actions.
| Code (Dec) | Constant | Description |
|---|---|---|
| 1000 | err_LoginFailed | Invalid username or password. |
| 1001 | err_AlreadyLoggedIn | The user is already connected to the server. |
| 1002 | err_AccessDenied | The user does not have the required Access Bit for this action. |
| 1003 | err_UserBanned | The user's IP or account has been banned from the server. |
| 1004 | err_ServerFull | The server has reached its maximum user limit. |
File & Transfer Errors
Returned during file system transactions (200-213).
| Code (Dec) | Constant | Description |
|---|---|---|
| 2000 | err_FileNotFound | The requested file or folder path does not exist. |
| 2001 | err_FileInUse | The file is currently being accessed by another process. |
| 2002 | err_DiskFull | The server disk is full; upload cannot complete. |
| 2003 | err_TransferFailed | The binary transfer was interrupted or failed checksum. |
News & Messaging Errors
| Code (Dec) | Constant | Description |
|---|---|---|
| 3000 | err_NewsFull | The news database cannot accept more posts. |
| 3001 | err_MsgRefused | The recipient has the "Refuse Private Messages" flag set. |
Field ID 100 (Error Text)
Sometimes, a server will return a generic error code in the header but include Field 104 (Error Text) in the parameter list. This field contains a human-readable string explaining the error in more detail (e.g., "Maintenance in progress, please try again in 10 minutes").
Last edited March 3, 2026 on the old MediaWiki site.
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Original wiki contributors: Lostarch
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Original wiki contributors: Lostarch