Edit page of form is blank

I went to edit one of my Forminator forms, I wanted to make the submit button conditional to stop accidental submissions and when I set the condition the screen went blank. Now all I see when I click to edit the form is the bottom footer, “built with wpmudev love etc”.

Basically I added a checkbox at the bottom on my form. I then clicked on the submit tab and set the visibility to only show when the new check box was selected. After that I closed the pop up that you edit in and the screen went blank. No refresh, no option to save changes, nothing. the whole form builder is gone.

The form still loads on the front end of the website and I can see it properly listed under Forminator Pro > Forms, but even when trying to export it and adding it to a new site I get the same issue.

Can a search and replace be done on the export code to remove the block of text that sets up the condition for the submit button?