Hi,
Thanks for reporting this issue and for sharing the sample code to reproduce. It's always much easier to analyse an issue like this when there is sample code available.
This issue is being caused by an
assembly co-location assumption inside the Nancy framework source code. This code is expecting all assemblies to exist in the same directory when the test is run - an assumption that doesn't hold true for NCrunch unless the
Copy referenced assemblies to workspace setting is set to TRUE.
Changing this configuration setting should solve the problem. Depending upon your solution structure, you may also need to change the same setting on other projects depended on by your test project.