Hi @Laura_Lynch welcome to our Community and sorry to hear about this trouble. For this kind of report, our Support team would be best equipped to assist you since we would need to look into the rule set up and error logs on your account.
Can you kindly reach out to Support and share the following information with them, please?
- A screenshot of the whole browser showing the rule set up
- The URL link for the project where the rule lives
- A screenshot of the error message you are seeing
This will help them investigate the problem for you.
I hope this helps!