I tried three different methods to build the engine using a drop-down menu in Visual Studio, and they all unfortunately built successfully for me. First I used the context menu from the UE4 project in the Solution Explorer.
This build ended with the result: ========== Build: 4 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========
Next I used the Build Project option in the Build menu with the UE4 project selected.
This ended with the same result as the first build.
Then I used the Build Only Project option in the Build menu with the UE4 project selected.
This one ended with the result ========== Build: 1 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========, but the Editor won’t open successfully due to missing dependencies.
In all three options for me, the OneSkyLocalizationService seemed to build fine.
Is there a different drop-down menu or option that you are using?
I also just re-read through the repro steps that you provided initially and realized that you are rebuilding your project in the later steps instead of just building it. Rebuilding the project in Visual Studio will also rebuild the Engine, which may explain why you see these same errors whenever you rebuild your project.