Thanks for the reply @w33zy.
The only button that causes anything to happen is the “attempt recovery” and that just gives me a blank page.
Interestingly enough, I can create new entires on my phone, but when I save them as a draft and try to edit them from my iPad, I get the same error. Makes me wonder if it’s something with iPad OS.
That said, the Classic Editor Plugin makes it all work. Thanks!
My apologies @ronaldvw.
Thank you so much @alchymyth, that did it!