Hi o7
At line 2,903 of KOTC Pathfinding plugin, the code tries to execute "return $KoTCPathMatrix1", I found that simply deleting this line of code stops the crash as well as continuing to work with Yanfly's Region Restrictions.
I don't know if this is advisable by Knight, but it's a working Band-Aid fix so far.
I may try it later, but you may want to comment out the line by putting // in front of it instead of deleting the line. I didn't get much use out of this plugin since it doesn't work with pixel movement (decimal coordinates)
I actually tried to get it working with pixel movement by rounding the destination coordinates to whole numbers, and it would work a couple times before inevitably crashing when it tried to go to a node with a float coordinate along the path to the destination
