I have a project that is using networked colocation sessions for MR experiences. I needed a way to view what the players were doing as a supervisor role and thus used the VR Spectator camera. The issue is that I needed to build a windows version that allows me to connect and control the camera (Which works), but whenever one of the players spawns in with a pawn that has ISDK (Meta Interaction SDK), it immediately crashes the windows version.
From your description it sounds like the crash may be related to how the Meta ISDK components are initialized in a non-HMD Windows build. The spectator client is not running in VR, but the pawn that spawns likely still creates XR or interaction subsystems that expect a valid headset and tracking context.
If the ISDK pawn initializes hand tracking, input routing, or OpenXR features on BeginPlay without checking the platform or XR availability, that could cause an access violation on Windows spectator builds.
You may want to:
Check if the ISDK components are wrapped with platform checks (for example, only initialize when running on Android/Quest).
Disable hand tracking and interaction subsystems on the spectator build.
Review the crash log for module load failures related to OpenXR or MetaXR.
Test with a stripped pawn (remove ISDK components one by one) to isolate which component triggers the crash.
This looks less like a spectator camera issue and more like a subsystem initialization conflict between ISDK and a non-VR Windows runtime.