“Reference could not be resolved” error when validating your architecture using Visual Studio architecture modeling tools

This post addresses a specific issue where architecture validation in Visual Studio 2012 and 2013 fails due to primary reference resolution errors when the reference is built against a higher .NET Framework version than the targeted framework. A workaround is provided by editing the modeling project file to set `<ResolveAssemblyReferenceIgnoreTargetFrameworkAttributeVersionMismatch>true</ResolveAssemblyReferenceIgnoreTargetFrameworkAttributeVersionMismatch>`.