OAM 11g R2 - Cannot add Federation identity provider with metadata

Hello,

We are migrating from OAM 10g with OIF to 11gR2 (SP included).

In our test enviroment we got a custom IdP application that works with OAM 10g so far. I wanted to add the IdP by uploading the metadata file to the oamconsole, the file is named c and attached.

When I press save i get the following error:

ADFC-10001: cannot instantiate class
'oracle.security.am.fed.oif.managedbeans.idp.EditIDProviderMB'

ADF_FACES-60097:For more information, please see the server's error log for an entry beginning with: ADF_FACES-60096:Server Exception during PPR, #37

And when I try to edit this Idp I always get the same error, and in the weblogic log I can read the contents of file a attached to this post.