97613.085 Error MainLoop.cpp:1195: Exception at tick 16330116: The mod Fluid Must Flow caused a non-recoverable error.
Please report this error to the mod author.
Error while running event FluidMustFlow::on_robot_built_entity (ID 14)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
FluidMustFlow/control.lua:457: in function 'endpointOnBuildRightFacing'
FluidMustFlow/control.lua:533: in function <FluidMustFlow/control.lua:525>
stack traceback:
[C]: in function 'index'
__FluidMustFlow/control.lua:457: in function 'endpointOnBuildRightFacing'
FluidMustFlow/control.lua:533: in function <FluidMustFlow/control.lua:525>

Thanks for ur report, should be fixed in the latest version (1.1.1).