ComfyUI Queue Stuck: Connection & Execution Checks
By Elmehdi ยท Updated October 5, 2026
A queue that appears stuck can reflect a disconnected browser, a long-running task or an exception in the backend. Check those separately before restarting everything.
Read the backend terminal first
If the terminal shows ongoing sampling or loading progress, the task may still be running. If it contains a traceback, read the final exception and the preceding node context. A quiet terminal alone is not enough to prove that the process has stopped.
Separate WebSocket issues from render issues
The browser receives progress through a connection to the backend. A WebSocket closed message means the connection closed; it does not identify the root cause by itself. Check whether ComfyUI is still running and whether your browser is using the correct address. For a remote server, also inspect the proxy or hosting connection limits.
Validate a minimal workflow
Save your current workflow, then test a small known-compatible graph with the models you have installed. If the minimal graph works, add the custom stages back individually. If it fails too, investigate the environment and server logs before rebuilding a complicated graph.
When a custom node fails
Use the node name and exception from the terminal to locate its official documentation. Confirm its dependencies and compatible versions. Export the workflow and use OnBeg to check missing connections, but remember that static JSON analysis cannot confirm that a custom node is installed or executable.
Before sharing a log
Remove tokens, private paths and credentials. Share the exact exception, relevant node name, versions and the steps that reproduce it. Do not treat a browser connection warning as proof that the workflow itself is broken.