We are trying to determine the cause to a crashing issue in our WPF application. Unlike other problems that cause our applications to crash, this specific issue crashes the application without any error reports in Event Logs so we couldn't determine the exact exception that caused the issue. We also couldn't find a way to reproduce the problem because it happens rarely and randomly.
After enabling process termination auditing, we've observed that when the problem happens, our application always exits with 0xCFFFFFFF (Application Hang), followed by WerFault.exe exiting with code 0x80070578 (Invalid Window Handle) or 0x80070005 (Access Denied). We suspect that WerFault exiting with errors is the reason that no error reports have been generated, but have no idea why WER isn't working. It is able to correctly generate error reports for other crashes happened in our application.