Tags stopped working, getting blank screen

Hello,

I’ve been having this problem a couple of days now. Whenever I want to access a tag, for example: https://www.tmff.net/tag/animation I get this weird blank screen with a ‘Choose file’ button. I had a look on the Internet but couldn’t find a solution.

This never happened before. The htaccess and index.php is the same when I check my latest backup and I have also tried to set my permalinks to default and then back again. When setting on default (plain), it redirected me on the home page, so the blank screen disappears. When setting it again on ‘Custom structure’ or ‘Post Name’, the blank screen appears again.

What should I do? I have also deactivated each plugin to see if one is causing this issue but this didn’t seem to solve it.

Thank you!