Hi,
could you tell us the version of llblgen you're currently using. I could not find the specific error message you gave in the current code base, as it seems that the messages for that kind of errors have been refined a bit since then.
It might be a problem with inheritence. Do you use per entity hierarchies?
Otherwise, your code seems correct to me.
A good way to target the problem is to recompile the Runtime libraries source code located in the "RuntimeLibraries" folder:
Open the solution, comment the lines about strong signing in the assembly info class, and get rid of the dynamic queries engine projects for the dbms for which you don't have the referenced assembly.
Then build the solution, insert the two projects (ORMSupport classes and DQE of your dbms) in your solution and make your generated code and your own code reference the projects instead of the dll.
Then you should be able to look for the error message, which should be located in the DataAccessAdapterBase class or in the DaoBase class according to your scenario (resp. adapter or selfservicing). Place a break point where it compares the root entity type from the prefetch path and the one from the prefetch path element, and you should see what goes wrong (climbing up the call stack might help after that point)
