Something went wrong - creating a form in Excel for the web in Sharepoint library

[SarahTurner]

I have created an Excel doc in a sharepoint library.  

I have gone to Insert / Forms / New Form 
It launches MS forms and then immediately says:

Sorry, something went wrong

Please make sure you have permission to access this form.

Technical details

Session id: bde6a9cc-7cf6-4b7e-82d6-3380526e161c, Correlation id: 675943ef-814a-4e7c-8b22-c8a31f1357d5

Please can someone help?