The methodology allows for multiple instances of "entry" classes. The tools accepts these multiplte instances and creates an XML element declaration for each of them, as expected. Th eproblem is that the tool includes the same set of unuqueness contraints in all these element declarations. Now these contraints have themselves have to have unque names, but in case of multiple such element declarations, the conatrsaints are also multiplied, using the same names multiply, which is not allowed as far as I know.
Proposal: either create set of contraints only once or give them unque names in all places.
Solved. All constrains now got a unique name.
Fixed in version 2.1