I recently had an error where I tried to install a nuget package in a project. From the nuget package console I got an error that it could not find it. I couldn't understand this as I could easily install the package in another project. But for some reason I could not install it into the project I had just created. I also checked the install tab in "manage nuget packages. I found nothing - the package was not there (which was also odd). I made sure I was looking in the correct nuget repository.
Then it hit me. The project I had just created was .Net 4.5. The nuget package was only built for 4.5.2. Visual Studio had by default created a 4.5 project. The error was simply a mismatch between the .net version of the package and the project. I simply changed the project .net version to 4.5.2. Then I could easily see and install the package.