5.3.4f1 project failing to build in Visual Studio 2015

I get CS0234 The type or namespace name 'UI' does not exist in the namespace 'UnityEngine' when building the project.

The UnityEngine.UI is in the references and appears to be properly referenced. Cleaning and rebuilding makes no difference. Re importing assets in the Unity project makes no difference.

Has any one else experienced this. Its driving me nuts.

Thanks
Dave

 

Try using the built-in monodevelop software that comes with unity. If that works, then you might want to stay there. If it doesn't, then it's not Visual Studio's fault.

 

breaks in mono development. Looks like missing .pps files whatever they are. The game runs fine in Unity.
Any way to clean up the build? This is an aspect of Unity I really hate - the hundreds of metadata files and other crap. There has to be a cleaner way to do that. Sigh.

 

My first theory was that Visual Studio wasn't working with Unity correctly but it seems that there's a problem of a completely different nature than I expected. I don't know much about that stuff, sorry :|

 

Thanks. This build has been perfectly OK. Committed it to source control and some files must have not been committed.
Really think all those files should be cleaner and tidier. I guess Unity is complex but no more so than other environments.