https://bugs.winehq.org/show_bug.cgi?id=57251
--- Comment #6 from Bernhard Übelacker bernhardu@mailbox.org ---
This is a Mono backtrace generated inside a win32 only wineprefix.
This seems related to my command line "wine KeePass.exe", which invokes a start.exe, which finally starts the 64-bit KeePass process. (msvcrt_init_io/GetStdHandle gets an invalid handle to stdout, therefore output is not visible.)
If I start with "wine64 KeePass.exe" then also the 64-bit wineprefix shows the Managed Mono backtrace.