Problems on targeting .NET 4.5.2 (Visual Studio 2012 with R# 2017.3.3)

Hi!

I'm using Visual Studio 2012, and wanted to target .NET 4.5.2 (installed the targeting pack).

After creating a WPF application there are a lot of resharper errors, but the solutions builds without problems.

The resharper errors seem like it does not recognize the System.Windows namespace.

Anyone encountered a similar issues?