Compilation error

[Zemogiter]

Describe the bug
While compiling the source code for this mod (to start working on a 1.3 update) I get this error:

Delegate 'Action<Rect>' does not take 0 arguments

in MainTabWindow.cs
The only changes to the source code are the ones from #52 and updating Lib.Harmony and Multiplayer API.
Expected behavior
Successfull compilation and the mod's dll files in output folder.