insert multiple inside standard DA insert form issue

I've fixed the page.

It appears there may be a bug in the extension. I see that all of the form elements on your page were renamed and had this appended:
_<?php echo $RepeatSelectionCounter_1; ?>

Only the fields INSIDE the repeated region should have been renamed. The renaming of all of the form elements is what caused the page to not work. I removed the appended value from the other form fields and that appears to have fixed the page.

(there was also an issue with the redirect url, the file upload code was too low on the page below the insert, and a missing hidden form element to pass the correct repeated language value. Those were more user errors than bugs, but I fixed those issues as well so that the page would work properly.)