forms are getting multiple submissions

What is the form setup? Are you leaving the form as is after submission? So, the users think it was not submitted and click again? I would recommend redirecting to some thank you page or, use reCaptcha for example.

It appears to be an issue with the systemFormComponents.min.js file. Users that have that file cached are getting a console error and the form is not submitting so they are hitting the button multiple times, clearing cache seems to fix it.

So my question now is, when I update JavaScript files I'll add something like '?v=1.01' to the end of the URL so it will automatically update for the end users who may have it cached. We have thousands of employees who use this site daily and I am not really sure what the best way is to get it to refresh for those users.

Are they using the forms on the live site? How to reproduce the issue using Dancing Goat? If those are employees, I would send them email and ask them to clear the browser cache. Or, redirect the form after submission to some thank you page.