Making package fail on purpose in blueprint if condition not met

I´d like to disable the packaging of a project via blueprint if a condition is not met. For example, using a wrong GameMode. I found a c++ snippet that would do the trick

//some complicated algorithm
if(some fringe case that you want to tell yourself if the runtime execution ever reaches this point)
	//"This fringe case was reached! Debug this!"
	UE_LOG(YourLog,Fatal,TEXT("This fringe case was reached! Debug this!"));

But I can´t find the way to do that with blueprint.

Thanks in advance!!