NUnit .Net unit testing framework

If there is a text file (or any other non-assembly file) in the 'addins'
directory, any add-ins in that directory are prevented from loading.

I've tested this with RowTest Extension for NUnit:
http://www.andreas-schlapsi.com/projects/rowtest-extension-for-nunit/

There is a 'readme.txt' file in my 'addins' directory as well as the
RowTest assemblies. When I select 'Tools > Addins...', the 'Row Test
Extension' has a 'Status' of 'Error'.

As soon as I delete the 'readme.txt' file, the RowTest extension will load
and start working.