[Cura won't open.]

Just found this. It seemed to fix things, but I still don't trust 2.5, so I reinstalled 2.4 since that was working for me.

https://ultimaker.com/en/community/software-and-firmware

https://ultimaker.com/en/community/39565-beta-testing-cura-25

https://ultimaker.com/en/resources/20499-reset-cura-2-1

[Cura won't open.]

Same here!!! I got 2.5 installed and it did open once but the materials window looked way wonky so I shut it down and restarted it. No good!! So then I uninstalled 2.5, rebooted, and reinstalled 2.4 and now THAT won't open either!!! I did a search of my system for "Cura" and got no results, but a MANUAL search of my system showed a butt load of plugin folders in a system folder named........you guessed it: Cura 2.4 AND Cura 2.5 that were never removed during the uninstall. Even a manual delete of both those system folders before reinstalling didn't fix the problem. I have a bad feeling that the 2.5 install jacked something in the registry and, just like those folders, didn't revert after the uninstall!! Stuck in the middle of a printer mod build with only half the parts printed, and FINALLY got my bed re-leveled, and NOW I don't have a slicer!!