Block broken and no ability to edit

Site URL: https://treefingers.productions

I have a portfolio section that has broken and I can't seem to get it working - it was fine up until about 4 days ago when I was showing someone my site for feedback (still a work in progress)  and the "credits" section wouldn't load. Now when I go into the editor it won't even let me make any changes or delete it. As in the dialogue box doesn't even appear, so I can't select any options. I tried adding a new section using the same template and I'm getting the same issue there before I made a single change to it. Does anyone have any ideas what has happened?

Try putting your site into safe mode.

Let us know how it goes.