failed to switch chat bot from baisc mode to workflow

[sinomoe]

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Dify version

0.6.8

Cloud or Self Hosted

Self Hosted (Source)

Steps to reproduce

1. create a chat bot in basic mode
2. switch mode to workflow
3. select llm node then error occured

✔️ Expected Behavior

select the llm node and then display the llm node detail

❌ Actual Behavior

an error occurred