Hello David,
Thank you for supplying your user key and screenshots of the error console. The errors I see on the backend look as if Form Mule is setup to run on an email template sheet. ( not the main sheet with the data to merge)
Also, there are probably many duplicate email templates (tabs with long names)
You can find these tabs by going to the bottom left-hand corner of your spreadsheet and clicking on the 'all sheets' icon.
(These duplicate email tabs can be created if job settings are recreated either because formMule is set up multiple times on the same spreadsheet or when formMule is accessed while logged into multiple accounts which can confuse the permission settings.)
Once you get the duplicate tabs deleted, you should be able to open up formMule, from the dropdown menu go to step1. "Choose source data and set merge type" and then make sure the correct sheet is selected.
Also, I see you have the timezone error (currently many others are experiencing this with Google Sheets)
In your spreadsheet, go to file > spreadsheet settings > change time zone. Change the time zone> save> and then change back to what you need it to be set as> save.
Thanks!