Crash when sending Dref for non loaded plane

[Patrickmaartense]

I noticed that xplane will crash when you send a dref for a non exisiting plane

eg:

cl300/dcp_navsrc
when no cl300 loaded will CTD xplane

latest Xplane 11.50b3 as well as 11.41

[Clamb94]

X-Plane seems to crash as soon as you send a dataref which doesn't exist. This problem did not occur in older X-Plane versions if I remember correctly