In any scenario where the Crawler is present Orbiter (here Orbiter_ng.exe) crashes.
The external graphic client seems to call the different callbacks in a slightly diffrent order than the inline client.
In Crawler::clbkPostStep() an acces to the not (yet) initialized member 'hLV' causes a crash.
I tested it with the RC30 of the D3D9Client. Maybe other versions behave different again, but the 'solution' should be fail-save in any case
"Guard" the access by if-clause. The method ( Crawler::clbkPostStep) will be called later on.
See attached patch file for a working solution