The type or namespace name 'HttpResponseMessage' could not be found

Hi
We have a project where NCrunch is used sporadically and so I'm not sure when this issue began.
It compiles correctly in visual studio but NCrunch has these errors for a project:
NCrunch: If you are experiencing problems in getting this project to build, have a look at http://www.ncrunch.net/documentation/troubleshooting_project-build-issues
Infrastructure\MediaContentUsage\Controllers\MediaReportController.cs (34, 10): The type or namespace name 'HttpResponseMessage' could not be found (are you missing a using directive or an assembly reference?)
Infrastructure\MediaContentUsage\Controllers\MediaReportController.cs (69, 10): The type or namespace name 'HttpResponseMessage' could not be found (are you missing a using directive or an assembly reference?)
Infrastructure\MediaContentUsage\Controllers\MediaReportController.cs (140, 10): The type or namespace name 'HttpResponseMessage' could not be found (are you missing a using directive or an assembly reference?)

I looked at the troubleshooting page, and tried a few things there, but could not resolve the issue.
When I compared the workspace folder with the project folder I found a lot of differences (there's much less in ncrunch workspace) and I'm not sure where I should focus.
The workspace packages folder is very sparse and does not contain System.Net.Http, I'm not sure if this is the issue, or how I'd get ncrunch to copy these packages.

Cheers.
Murray.

Hi, thanks for sharing this issue.

Could you confirm whether you're running the latest version of NCrunch? We have had fixed targeted to references pointing at this particular library in the past.

Also, does compatibility mode make any difference?