Not sure but could you please try to disable the Native .NET tool chain for release mode? You can find this checkbox in Properties - Build page, then select your platform target and disable "compile with .NET Native tool chain". If there is something wrong with the release mode but debug mode works, I'm guessing it is related to the Native .NET tool chain.
Exception at app start in release only.

Gavin Williams
721
Reputation points
Sometimes when i run my app in release, I get the following error ..
Unhandled exception at 0x7F50CCE0 in UWPPopupsIssueDemo.exe: 0xC0000005: Access violation executing location 0x00000000.
I haven't seen the issue in debug. How can i go about fixing this?