Issue: Plugin redirects to /wp-admin/upload.php?page=add-from-server

Hello.

It has been a while since I last used the plugin (some two years ago, give or take a few months) and back then it worked perfectly fine; I had no issues with it. Now that I’ve started using it again after pretty much everything (including the plugin itself) has been updated to the latest version, it has started acting oddly.

The issues is this: whenever I start using the plugin, it starts to work normally for a little while, moving anything from a single file to some ten files before the page redirects to *homesitehere*.com/wp-admin/upload.php?page=add-from-server and produces the message “Oops! That page can’t be found.” After each time this happens, only some of the selected files (number of which does not exceed 35), all within the range I mentioned, have successfully been converted.

Can you offer some insight as to what could be causing this? Your plugin has been quite essential for me in the past.