Random assembly references fail (“Are you missing a using directive or an assembly reference?”)

Question

My application has a mixture of 3.5 and 4.0-targeted assemblies. I\'m working on a new Windows service targeting 4.0 and the project suddenly seems unable to see some of th

Answer 1

I was adding projects to a Solution that utilized .net 4.5. The projects I had added were defaulting to 4.5.1. This rendered 4.5 libraries incompatible with the new projects. I went into the properties of my new projects and had them target 4.5 instead of the default 4.5.1. After I had done that, my solution was able to build.