I'm not with Laminar Research, just a fellow simmer in the UK.
I have looked through you Log.txt file and the first thing that sprang out of the page was the sheer amount of custom scenery files that you have installed!
Why could this be relevant, well in other cases where XP11 simmers have had similar crashes, they too have hundreds of custom scenery files, just like you do, and they too have had a return_is_nan(flt[p0].ax_wrl (fm_indi.cpp:90) message in their Log.txt file.
I'm not suggesting that the custom scenery files are definitely the problem, but it is at least coincidental.
Further, the return_is_nan(flt[p0].ax_wrl (fm_indi.cpp:90) message occurs during the point where ATC is trying to deal with all of the scenery files, posting messages in the Log.txt file such as:-
0:02:58.461 I/ATC: Airport flow changed at KSLI!
CurFlow: AUTOGEN: North NewFlow: AUTOGEN: West
0:02:58.461 I/ATC: Changing KSLI CabState from 0 to 1
0:02:58.461 I/ATC: All departures are done at KSLI. Advancing...
0:02:58.461 I/ATC: Changing KSLI CabState from 1 to 2
0:02:58.461 I/ATC: All arrivals are done at KSLI. Advancing...
0:02:58.461 I/ATC: Changing KSLI CabState from 2 to 0
0:02:58.461 I/ATC: Airport flow changed at KTOA!
The following single message was posted on three separate occasions:-
0:02:58.461 W/ATC: Could not find an appropriate flow at KRIV...attempting to autogen one on the fly
0:02:58.461 W/ATC: Adding autogen'ed flow AUTOGEN: West to the list for KRIV
Whether there is a problem with the KRIV custom scenery file only, or with all of them I'm not sure, but it might be worth cutting and pasting all of your custom scenery files somewhere safe and outside of the XP11 file structure, just to see if anything changes with the 'crash' scenario?
Sorry, not sure what else to suggest?