Having some pretty odd issues with ad hoc MP with my friend crashing intermittently

Not sure what the exact issue is, there doesn't seem to be a real pattern to it. Sometimes its just a crash to menu but sometimes its a crash from the kernel itself. we are running modded with Xskills Fork and its dependencies as well as BetterRuins which should be stable in MP? we did have Realistic Water also enabled to start with but disabled it when we were hoping it would solve the problems.