the problem did not go away even, when only building the firmware dll.
So I cleared all Mono and Xamarin stuff from my laptop and started from scratch with Mono 3.2.3 and Xamarin 5.0.1.
After solving some problems with ASP-AddIns, I finally managed to build the most simple “hello” world” command-line, but with the .Net-runtime only. As soon as you try to build with mono, I get the error
Could not find type ‘System.Globalization.SortVersion’.
again. There definitely seems to be a general error in mono.
I tried to get more updated mono versions. The mono-project still sells V3.2 as V3.4, which is available for macOS only. I found an interesting article on code-project () how to build more recent mono versions from source code. But the V3.4-binaries provided there didn’t solve this problem.
I hope this helps a little bit in getting the next mono-brick-version running for windows-user, too.
If can help somehow, please let me know.
P.S.: When releasing the next SD-card-images, could you reduce the size a little bit (e.g. 4GB->3.8GB) to avoid the “does not fit”-error which I experienced, too.