I tried all of the above solutions numerous times but none worked for me. I was using Visual Studio 2015 with ReSharper 9.0.
I was able to resolve this by upgrading to ReSharper 9.2. If you already have the latest update for your major version, maybe reinstalling ReSharper might fix this for you. I would suggest clearing you ReShaper cache first, just in case.
Here's the link to the archive versions of ReSharper: https://resharper-support.jetbrains.com/hc/en-us/articles/207242355-Where-can-I-download-an-old-previous-ReSharper-version-