Cause
This error occurs if you attempt to redefine a class map.
Specifically, a class map has already been defined indicating which file will hold instances of a particular class and the schema file attempts to redefine the class map to use a different file.
Action
Remove the redefinition of the class map, or modify it so that it matches the existing definition.
Refer to your JADE messages (jommsg.log) log file for more details about this error.