I have been using the schema generation tool to generate my database (in Oracle) from my mapping file successfully for some time, but am now getting an error :
Schema text failed: could not instantiate id generator:

There is no additional information and no stacktrace, and I cannot determine why this has happened - it has worked before, and i have not made any changes to the id generation. The error messages are never very discriptive, but stack traces usually give me enough information to find out what's going on - in this case I can't think what could have caused the error.

Has anyone come accross this problem before?