Next Terminal

RDP/VNC Error Codes ​

When connecting to remote desktops using RDP or VNC, you may encounter errors. This document lists common status codes and meanings for faster troubleshooting.

Status Codes ​

Next Terminal uses a unified numeric status-code system to represent success/failure states.

Success ​

0 (SUCCESS) ​

Operation completed successfully.

Unsupported Operation ​

256 (UNSUPPORTED) ​

Requested operation is not supported.

Server Errors ​

512 (SERVER_ERROR) ​

Internal server error. Operation cannot be completed.

513 (SERVER_BUSY) ​

Server is busy. Operation cannot be completed.

514 (UPSTREAM_TIMEOUT) ​

Upstream server did not respond in time.

515 (UPSTREAM_ERROR) ​

Upstream server returned an error.

Resource Errors ​

516 (RESOURCE_NOT_FOUND) ​

Related resource (file/stream etc.) was not found.

517 (RESOURCE_CONFLICT) ​

Resource is in use or locked.

518 (RESOURCE_CLOSED) ​

Related resource has been closed.

Upstream Connectivity Errors ​

519 (UPSTREAM_NOT_FOUND) ​

Upstream server does not exist or is unreachable.

520 (UPSTREAM_UNAVAILABLE) ​

Upstream server refused the connection.

Session Errors ​

521 (SESSION_CONFLICT) ​

Session ended due to conflict with another session.

522 (SESSION_TIMEOUT) ​

Session ended due to inactivity timeout.

523 (SESSION_CLOSED) ​

Session was forcibly closed.

Client Errors ​

768 (CLIENT_BAD_REQUEST) ​

Request parameters are invalid.

769 (CLIENT_UNAUTHORIZED) ​

Authorization denied because user is not authenticated.

771 (CLIENT_FORBIDDEN) ​

Permission denied. Logging in cannot resolve this.

776 (CLIENT_TIMEOUT) ​

Client response timeout (usually browser/user side).

781 (CLIENT_OVERRUN) ​

Client sent more data than protocol allows.

783 (CLIENT_BAD_TYPE) ​

Client sent unexpected/invalid data type.

797 (CLIENT_TOO_MANY) ​

Client has consumed too many resources.

Troubleshooting ​

Timeout issues ​

  • 514, 522: check network and remote desktop server health
  • 776: check client network, refresh and reconnect

Authentication issues ​

  • 769: verify username/password
  • 771: verify permission settings for remote desktop access

Server-side issues ​

  • 519, 520: verify remote host address/port
  • 513: retry later when server load is lower

Session conflicts ​

  • 521: check whether same account is in use elsewhere
  • 523: ask admin to check session management settings

If you encounter an unlisted code, contact the administrator and check server logs for details.