Penned in places when pensive thoughts pondered...
Arise, awake, and learn by approaching the exalted ones,
for that path is sharp as a razor’s edge, impassable,
and hard to go by, say the wise.
Because every single reason has the same, if not more, number of reasons to be wrong. ;)
It seems that many have found NUnit 2.5.5 not working with DLLs compiled with .net 4.0. NUnit 3.x has been designated to work with .net 4.0; till that time make a modification to the NUnit config file and add this startup element under the main configuration element :