[Forminator Pro] Forminator Form error after submitting

I was able to integrate Google Sheets to one of my forms, but after clicking Submit button I get the following error “An error occurred processing the form. Please try again”.

The email notice is NOT sent but the record is going to the Google Sheet, so I guess something regarding the email send part is failing.

Already tried from another computer/browsers with no luck and can’t figure out what could I have missed in the settings.

How can I diagnose/fix this issue?