[Bug Report] Sagemaker data wrangler: An error occurred loading this view

**Describe the bug**

I import my data from Athena, then add a new custom data transform. As soon as I click on the "Custom transform" option, the error occurs with message: An error occurred loading this view. There is no other useful message to find out the problem. Please tell me how to troubleshot or fix this problem. Thank you in advance.

**To reproduce**
- Import data from Athena
- Add transform
- Add step, choose custom transform

No repository file, test, or entry point is named. Reproduce the flow by importing data from Athena, adding a transform step, and choosing Custom transform; done means the view loads successfully or reports a useful diagnostic that identifies the cause.

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