Using GSOUT in safety logic circuit stops the robot

I ordered a DX200 with a FSU unit mounted. There's a rather complicated perimeter fence logic so the wires of the fences and barriers go directly to the FSU terminals. I need to activate a lamp but all the pins of the safety relays are occupied by the robot, so I looked up and found I could use a general output from the robot, per this manual.

So I enabled this output in the safety logic circuit, but it stops execution. Whenever the circuit triggers the pendant shows M-SAF GENERAL OUT FB DIAG. ERROR. Is this the default behavior? There's times where I need the lamp but the robot shouldn't stop working (muting, for example).

Hmm, where's this option? In the maintenance menu there's no machine safety function parameters.

Okay, it's there, thanks. Indeed, turning off the feature lets me use the output as a normal one.

Thank you both.