Cannot change Target Framework on Several Projects From v4.0 to V4.5 or 4.5.1

Question

I have several projects in a large solution that won't convert to V4.5.1 (or even V4.5). Most did, but obviously I need to get all of them converted. The GUI in Visual Studio says that it did it and reloads the project, but if you go back into the properties it still says V4 and it won't compile because of dependencies that converted properly and are V4.5.1

I tried manually updating the .csproj files and it says 4.5.1 as the target framework, and I even updated the app.config/web.config to point to the right version, however Visual Studio's property page still says .NET 4 and is throwing compile errors because it can't access the ones that successfully updated to 4.5.1

What am I missing in the process to get these updated? I've tried VS.net 2012 and 2013 and both do the same thing.

Answer 1

In hopes that this helps others:

In our case, the issue was that we were referencing a custom targets file that was created for the entire solution. even though the project was getting updated, the custom targets file was overriding it thus preventing the project from getting updated.

Updated the targets file to point to .net 4.5 and everything was fine.