"messages.117" error with the AI builder

Yesterday I tried the AI builder for the first time and it worked. I consumed about 25 credits. Today I opened the same workflow and the first prompt led to this error message:

messages.117: tool_use ids were found without tool_result blocks immediately after: toolu_vrtx_01Ra3f4M1FXTKGHJ496E7bcD. Each tool_use block must have a corresponding tool_result block in the next message.

It looks like a langraph error. But there’s no AI agent or AI node in the workflow.

What should I do? I just can’t use the builder.