Hi @shelleyb
Please try to pass Static name in create file Action for example Test.xlsm and then verify I think you are trying to pass invalid or Empty value in Name field of create file Action which you select dynamically.

--------------------------------------------------------------------
If I have answered your question, please mark post as Solved.
If you like my response, please give it a Thumbs Up.
Contact me if you are interested in custom Power Automate development.