If you neglect to make the constructor on a test fixture public, the NUnit test runner will complain that the fixture is invalid with the misleading reason 'the fixture contains no tests'.
... until the collector arrives ...
This "blog" is really just a scratchpad of mine. There is not much of general interest here. Most of the content is scribbled down "live" as I discover things I want to remember. I rarely go back to correct mistakes in older entries. You have been warned :)