Windows 10 x64 v1809 Build 17763.6293 (Hardware)
XnViewMP v1.8.0 x64 (Setup) [installed on OS; runs in sandbox → Sandboxie]
and
Windows 10 x64 v1809 Build 17763.6054 (virtualised 'guest')
XnViewMP v1.8.0 x64 (Setup) [installed & runs native on OS]
Description of steps to reproduce the path which lead to crash:
In Windows-Explorer
right-click a folder with plenty of pictures and videos (about 4800 files plus subdirs)
choose "Betrachten mit XnView MP" (Browse with XnViewMP)
Wait while thumbs are building up (reading database?).
→ Application crash (with crashdump)
The issue can be reproduced!
I had to go back to v1.7.2. on both machines.
XnViewMP v1.7.2. does not have this issue.

Kind regards
eremit