VS 2019 16.10.0 Preview 2.1 'Build' Menu has no 'Build' entry

Question

I installed VS 2019 16.10.0 Preview 2.1.  The first solution I tried to load - failed to load.  So I tried to Create a C# solution (the "Hello World" one) which created the canned source fine but I noticed the "Build" menu had no 'Build' or "Rebuild" entrys.  The "Build" dropdown menu ONLY has "Run Code Analysis" in it.

 

I loaded another Solution I had which loaded fine but same no 'Build'/'Rebuild' entry.

 

I uninstalled and re-installed -- with the same results.  Next I uninstalled and deleted all intems/files in the path and Reinstalled Visual Studio.

 

After reinstall I had the "Build..."  menu items back and could build the "Hello World" simple one, and I could bild/run two of my Projects but the original one would not build still.

 

I feel I must have corrupted one of the Soulution files (.sln or .suo, or .csproj) but cannot see anything obviously wrong and am not sure what file controls whether or not the correct files are there to show the "Build" menu items.

 

Can anyone help me out here?

 

Ned Evans