Upgrade Webi Document from BI4.0 to BI4.1

Hello,

I just installed a BI4.1 SP2 Platform.

I want to upgrade my Webi Docs from my still existing BI4.0 environnement to this new Platform.

I tried with the LCM and UMT (using -internal_use_only_noversioncheck parameter)

Objects are imported in the BI4.1 repository, but i cannot open Webi reports from the launchpad.

Is there a specific procedure to upgrade webi docs from a 4.0 Platform?

thanks

Xavier