Tachyon renderer sometimes gets stuck
Once in a while the Tachyon renderer seems to get stuck doing nothing (does not seem to use any CPU) and Ovito freezes and becomes unresponsive. It seems to happen randomly (e.g. restarting Ovito and rendering the exact same thing works). I do not recall it happening when rendering just a single frame, but this may be because it happens quite rarely, and rendering an animation with a lot of frames simply increases the probability of it happening at some point during the rendering.
This is with Ovito 2.8.2 on Windows 7.