Freezing/Crashing Issues

[Zeep]

I'm having an issue where whenever I left click basically any button in the game (Options, apply buttons, parts in hangars, actions for kerbals, anything at all.) the game stops responding and flickers between the game screen and my task bar then tabs out and I am unable to tab back into the game in any way. I'm running from a new download and haven't done anything with mods. I've also verified the integrity of the game cache on steam and no problems have come up. I've reinstalled the game a few times but it didn't help. I don't know what the issue is and I don't have any crash logs because the game doesn't actually crash, it just freezes then tabs out. If you need computer specs or anything I can provide them.

[diomedea]

Honestly, doesn't seem an issue tied to KSP, but to hardware/OS. Those symptoms are similar to what would happen if a stream of Alt-Tab was sent from Keyb (or any input device configured in a similar way), but the same would show should the task switcher hang (something I've noticed, other buggy software active on the system can cause this). Also, Windows has "features" like permanent keypresses that always get in the way (activate automatically at the worst of times) and could have a role in this.

Anyway, seems clear the actual left mousedown action (the left click) isn't passed to KSP and therefore isn't processed by the game. It is "consumed" at the OS level that responds switching focus in and out repeatedly. Can't tell what caused the OS to behave like that, but my advice is to

1) verify system settings, could be some "feature" is enabled; also, check how the system performs with a mousebutton test;

2) disable peripherals you don't need (should those be shooting events at the OS);

3) stop/close all unnecessary background programs/services (and don't let the unneeded ones to automatically restart until you can be sure they have no effect).