A Decision Tree for Broken ComfyUI Workflows

Stop Guessing, Start Diagnosing

When a workflow breaks, don't reinstall blindly. Follow this decision tree — it's what we use in remote sessions.

Decision 1: Can ComfyUI Start?

Check http://127.0.0.1:8188/system_stats.

• No → Fix Python/PyTorch/CUDA first. See Common Issues.
• Yes → Go to Decision 2.

Decision 2: Missing Nodes?

First rule out frontend-only nodes (Note, Reroute, PrimitiveNode, workflow>*). These are normal.

Real missing node → check if plugin folder exists in custom_nodes/.

Decision 3: Plugin Exists But Node Missing

Check logs for IMPORT FAILED:

• Missing package → dependency issue
• Code error → source compatibility (update plugin)
• Name mismatch → node was renamed

Decision 4: Node Works But Errors on Run

• Error mentions model path → missing model, not a plugin issue
• Error mentions Python module → dependency issue

Decision 5: UI Stuck on Loading

Console says "Starting server" but browser shows nothing. ComfyUI did start. Culprits: Manager fetching remote data, BizyAir API retries, large workflow rendering. Set Manager to offline, set BIZYAIR_SKIP_TRD_MODEL_CACHE=1.

The Key Insight

90% of issues are: missing plugin, dependency conflict, code incompatibility, or missing model. Identify which in 2 minutes. Full reference: Troubleshooting Decision Tree.