Hi,

It is an error that should not occur.
Try rebuilding.

Internal compiler errors usually mean the compiler itself had an access
violation.  They're almost always bugs in the compiler, though occasinally
setup problems may cause these as well.

For the C# and Visual BASIC compilers, you can use the /bugreport option to
generate a file containing all your source, your compiler command line
options, some data about what version you're using, and some simple notes
from you about what you expected to happen.  These are invaluable to the
compiler developers to help reproduce your problem, so they can diagnose &
fix it.

If you get an internal compiler error, please generate a bug report and
post it on a newsgroup for your language.  Your compiler vendor will want
to know about it.

Brian Grunkemeyer
MS .NET Framework Base Class Library team