I think RC is right. I ran into this a while ago and the answer is longwinded at best
It has to do with FLS Slots. Someone made a free plugin that checks how many slots you have available. Running some plugins as a separate process helps resolve the issue though. As does using more JS plugins.
https://www.gearslutz.com/board/musi...fls-limit.html
You could read that thread for more info but link to the plugin could probably be found by googling "FLS Checker"