Transformation activation problem

Hello All,

after saving a transformation it results a failure of the system.

No errors are displayed but something goes wrong: after saving the transformation, it looks like it is saved successfully (as I can read on the left bottom) while simultaneosly I see that the transformation is still not saved (as I can read under Version).

Moreover even if I try to delete a Rule it still remains on the screen.

Saving one more time the transformation leads to the same result.

No further updates are saved even if the system replies with "Transformation saved successfully".

Thanks for any help.