The following discussion is based on the code in version 2.3.0.

• FXeSSRHI::FXeSSRHI() registers some callbacks, which are canceled OnPreShutdown.

• However, if XeSS is not supported in the case of DX11 Mobile Preview, FXeSSModule::Init() will call XeSSRHI.Reset() (XeSSModule.cpp line 81) . It will destruct FXeSSRHI, making the callback invalid.

• Perhaps we should confirm that XeSS is supported before adding the callback?