Hi Vapi team, I’m encountering a blocking issue that is preventing my workflows from saving or performing any operations. The system keeps returning the error:

node tool credentialId must be a uuid

I have already: • Assigned a valid UUID credential • Recreated the affected node(s) • Checked that there are no blank

credentialId

fields in my visible configuration Despite this, the error persists and the workflows cannot save or execute, which is completely blocking my development. Affected Workflows: • https://dashboard.vapi.ai/workflows/737cf8a9-7c2e-4288-8c6f-6d2c67bb6583 • https://dashboard.vapi.ai/workflows/d36dce29-cc7f-4ec4-b875-3e55648bb7be This appears to be either a hidden credential reference or a corrupted workflow state on the backend. Could someone please investigate or reset the credential reference for these workflows? This issue is currently stopping my work entirely. Thank you — I would appreciate urgent assistance.

Hey @SAIAH, I see why this credentialId must be a uuid error is blocking your workflows, often it’s caused by hidden references or a corrupted node state that standard UI checks don’t reveal. I can help pinpoint whether it’s a lingering hidden credential, a backend mismatch, or a workflow import issue. Quick question: were these nodes created fresh or copied from another workflow? Knowing this helps me advise a precise fix or reset so your workflows can save and run without errors.

Hey thanks for getting back to me, the first workflow https://dashboard.vapi.ai/workflows/d36dce29-cc7f-4ec4-b875-3e55648bb7be was copied from one of my previous workflows on another account. while this workflow https://dashboard.vapi.ai/workflows/737cf8a9-7c2e-4288-8c6f-6d2c67bb6583 was just newly created from scratch

Hey, that context helps a lot. When a workflow is copied from another account, it can sometimes carry a hidden credential reference tied to the old account, which triggers the credentialId must be a uuid error even if everything looks correct in the UI. For the copied workflow, the best fix is usually recreating or rebinding the tool node so a fresh credential UUID is generated. For the new workflow, it could be a node state/credential serialization issue during save. I’ve handled similar workflow state issues before and can help pinpoint exactly where it’s breaking. If you want, feel free to DM me and we can sort it out quickly. @SAIAH