[TWW3 5.0.0] Clicking issues and major graphics error makes game unplayable (video included)

The game has been mostly okay up to this point, but suddenly became unplayable today. I haven't updated the game or my computer the since last time I played, so nothing should be different.

*The game usually runs fine for a few minutes.
*The first symptom is that I sometimes can't click on things.
*Then, after a few minutes, the graphics glitch out completely, and I have to Alt+F4 out.Trippy lightshow: https://streamable.com/4pg8wc (sometimes the box is stationary instead of bouncing around)


I've tried switching out the mouse, restarting the game, rebooting my computer, and changing from fullscreen to window mode.I've also tried loading older saves, and saves from a different campaign (although the problems happen even on the new campaign screen, as seen in the video).

I would like to finish my RoC campaign before I update the game, and I assume older saves are not compatible with the newest version.