BI4.1 SP3- Webi migrated report and hidden class

Hello,

I'm trying to migrate a universe and its related documents from a XIR2 sp3 platform to BI4.1 SP3.

In the universe there is a hidden class with several predefined conditions within.

I got reports that won't work anymore in modification mode because one of this condition cannot be found. When i try and go to the query panel i get a not available object error and when i click OK the condition has been withdrawn from the panel. And i cannot had it again because the class is not visible.

I got other reports based on other conditions of the same hidden class and that are working correctly.

If i unhide the class and re export the universe all the reports are ok.

How come that one specific object within a hidden class cannot be seen by my report? it is non sense to me

No access restriction defined for this universe...

No incompatibilities defined for this objet with other tables in the query...

Have you heard about problem like this and related to this service pack of BI4 or to migration process?

thanks

Xavier