I am moving various plates - when the rotation angle gets above 180 degrees, the simulation breaks down and I get the error “Stage rotation takes long path”. I saw others suggesting that I use the “LongPathTool” but I can’t find it anywhere.
As far as I know, if you’re doing a 180°+ rotation, you’re going to cross the positive/negative flip. So the options are either to make it a smaller step and half the rotation or change it to the oposite manually so for example 200° = -160° because 180° = -180° so +10° in the positive direction is -10° in the negative.
As for the longpathtool, I’m not sure. I know there is an option in python and also that gplates normally should give that error and then an option to save the rotation file, which will automatically correct it. If that didn’t happen, do the manual stuff. Hope it helps 
Yes saving the rotation file in GPlates should correct that, as MrUks noted. When you load the rotation file it should result in unsaved changes (you’ll see it as coloured red in the Manage Feature Collections ctrl+M dialog). Saving it should then make it take the short path.
The longpathtool seems unrelated to this - that’s probably about long filename paths in Windows.