Lol, I used to get this issue way before 2020 and occasionally to this day.
FIX (at least for my system): Hover over "Save" => Smash Left + Right mouse buttons in very quick succession and alternate the both sides ;)

Ah thank you for the response, too bad Keen is occupied making DLCs, and not with fixing their shit.

Don't think I've removed, just not included them... Good observation though. The problem for me and few others has been that once I enter the PB edit page, there's no way out of it. The buttons do nothing and it softlocks the game rendering the block unusable. They work for most, but not for me and if something goes wrong in the script, a keen update on the game or script gets updated, I have no way of updating the BP using said scripts, which is why I just don't put scripts in for now.

Amazing as always.

I'd like to have a question, I've been seeing you removing PBs from builds and saying that they are broken. I've taken a brake for a few months from SE and I didn't really follow the news, what happen to PBs?

Really cool