Troubleshooting
Android Assert (Check/Ensure/Verify) crashes are not showing up in Backtrace for my debug builds
Backtrace currently doesn't handle the Assert crashes typically associated with Debug builds on Android. This is not a problem in release builds, where these types of conditions tend to be compiled out. For more information on Asserts, see the Unreal Engine Documentation.
How can I troubleshoot failures in crash reporting?
Please refer to your crash reporting client logs.
Make sure the DefaultEngine.ini (for crashes in packaged builds) and UserEngine.ini files (for crashes within the editor) have the correct settings. For more information, see Initialize the Backtrace Client.
Cooked Builds
When creating cooked builds, the contents of [ENGINE_DIR]\Engine\Programs\CrashReportClient\Config\DefaultEngine.ini gets included as Engine\Programs\CrashReportClient\Config\DefaultEngine.ini in the cooked build's path.
Even though the CrashReportClient.ini files generated in the Saved directory have the Backtrace URL, they appear to be using the file from the Unreal Base directory instead.
When you replace the contents of the CrashReportClient.ini file with the Backtrace version, the reporter works as expected.
You can use networking tools like tcpdump or FiddlerEverywhere to verify that the CrashReporter is submitting to the correct host.