When working with some Linq today, I kept getting the following error:
String must be exactly one character long.
This one had me scratching my head for a while. Turns out the problem was in
the Linq to SQL designer, and the way the code generator interpreted results from
the view I was using.
To remedy this, go back to the designer, pin the Properties sidebar open, and look
at the elements which have been mapped. Any one which is mapped to Char(1) should
be changed to a String. This should fix your problem.