Custom module not importing

I have a custom module builted with module builder. Everything seems fine but when I try and use the import function for that module I cannot get pass the fields mapping confirmation page.

I get a javascript error on there so I’m assuming this is what is breaking the ‘next’ button to proceed

Have you run a Quick Repair & Rebuild after configuring/deploying the module?

Is it anything to do with the data in the CSV?