It might be useful to check the command line that was used to start the program.
Open the Details tab of Task Manager and right click on any column (Name/PID/status). Then choose "Select columns" and in the new window scroll down and check the "Command line" box (below the I/O ones).
You can debug .NET code with an assembly debugger of your choice, it's fun, and sometimes, the only way to spot rare and nasty issues. However you'll end up on having a lot of noise since you'll debug the virtual machine of the .NET runtime, losing what the original .NET code was intended to do.
To debug .NET code and assembly at the very same time you can ...