Hi @DanG,
Could you please share a Loom with an overview of your setup, an example of the issue in the Debugger tab, and the Custom Function code and configuration? That would help us get a better understanding of what might be causing the function to error out.
Also, feel free to check out the Custom Function section in our Troubleshooting guide:
https://community.mindstudio.ai/t/troubleshooting-guide-101/71#p-104-custom-function-error-5