Troubleshoot ports
Fix missing ports, failed forwards, expired previews, and process safety errors.
On this page
A port is not listed
The process may have started outside Glueprint, or detection may not have been able to tie it to your work. Use + Add port to register it manually.
System ports below 1024 and Glueprint’s own engine and control ports are excluded on purpose. Glueprint’s control ports are never listed or forwardable.
A row vanished
The server stopped listening. Detection removes dead rows within the next scan tick.
A forward fails
Check these common causes:
- The remote host is offline.
- Your plan is below Pro.
- The host, viewer, or forward has reached its cap.
See Forward ports from another host for the exact caps.
A preview tab shows 401 or 404
The preview session expired or is no longer known. Return to the workspace Ports popover and open the port again.
Stop process says “process changed”
The operating system reused the process ID after Glueprint detected the port. Refresh the port list and try again.