About the strange thing asking for a uproject: Well, which uproject files should unreal open, if you launch it via the debugger? The engine is a central project, that is NOT unique to your game, so if there is more than one project, the engine could not possibly know which project you want to run - that is why it asks. However you can set the default project, so future startups will actually know.
Furthermore I have looked into the code responsible for debugging - UE uses the WIN32 function “IsDebuggerPresent” to check during startup if a debugger is present. Only in this case it disables the use of SEH. There seems to be no command line switch to disable SEH, however there is a macro PLATFORM_SEH_EXCEPTIONS_DISABLED to disable SEH completely, which is not what I want in my case. I would like to start UE on my machine without SEH, so it also asks for a debugger in case of exception, and with SEH in case it gets started on a designer’s machine, so it uses the crash reporter there.
locations in code:
LaunchWindows.cpp, look for line (184 in my case):
if( FPlatformMisc::IsDebuggerPresent() && !GAlwaysReportCrash )
Here GuardedMain is called instead of GuardedMainWrapper. The later contains the SEH handler that catches the page fault and calls the crash reporter.
If you start UE without the editor compiled in, then the crash reporter will not be enabled by default and must be enabled by using the “crashreports” command line switch. However there seems to be no possibility to disable it when you use a development configuration with the editor.