El mod Utilization Monitor (Blargh) (0.8.5) causó un error irrecuperable.
Por favor, informe de este error al autor del mod.

Error while running event UtilizationMonitorBlargh::on_init()
UtilizationMonitorBlargh/control.lua:243: attempt to index field 'filter' (a nil value)
stack traceback:
UtilizationMonitorBlargh/control.lua:243: in function 'add_entity'
UtilizationMonitorBlargh/control.lua:366: in function 'reset'
UtilizationMonitorBlargh/control.lua:425: in function <UtilizationMonitorBlargh/control.lua:424>

That's a very strange place for there to be an issue - it's in the part of the code determining the maximum flow rate for a found boiler.

Do you have any other mods that add things like boilers?

If I use this MOD that adds some new boiler.
Random_Utilities_2.1.1

Sorry for my English. I'm Spanish

Try version 0.8.6 and see if that fixes your problem?