I strongly encourage you to post your problems with fuzzylite in the forums at http://www.fuzzylite.com, where I and others keep track of them and we are very happy to help you.
I believe the error you are finding is due to warning C4702 being raised during compile time.
This is happening in fuzzylite v.4.0, and a solution is to add in file fl/fuzzylite.h
the following line within the #ifdef FL_WINDOWS
(together with the other #pragma
s):
#pragma warning(disable:4702) //Ignore unreachable code
For future reference, please refer to the forums at http://www.fuzzylite.com