Kerbal Space Program

Other users having reporting problems like this found that if they turn up their anti-aliasing to 8x (or the max they can support) that these types of graphical glitches often go away, but even with mine at 8X, I sometimes see icons vanish completely only to return when I go to another part group and come back so there may be more going on, like differences in what filter layer they get changed to, or z-overlap or something. I've recently started exploring Unity myself and found some of the icon pallets to be hiding graphics that should be visible, and then later Unity updates quickly fix that, so I think this may just be another Unity bug that crept in just before the release build was compiled... but that is only a guess.

Try raising your anti-aliasing though. It might help. If not, you'll need to upload your settings.cfg file along with the KSP.log file to help isolate common settings that lead to this anomaly. Close KSP before attempting to upload the files so the logs can be closed out. It is helpful if you just open KSP long enough to go right to the error, then press Alt-F4 to close it quickly.

Closing in effort to database cleanup.