Adding users to an existing role by copying from other Porta

[mosrei]

Hello,
We are uprgarding from Portal 7.00 SP15 to Portal 7.01 SP6. Both Portals are conected to the same LDAP.
We are trying to copy the relation between the role to the users by using the import option from User Management.
After pressing the upload button in the upgraded Portal, we receive the following error message:
Error: Attribute "description" on namespace "com.sap.security.core.usermanagement" of principal "ROLE.PCD_ROLE_PERSISTENCE.2axUd2qUDZX3ORyv4DV2HLmzeRs=" is not modifiable.

Our upload file looks like this:
role]
rid=pcd:portal_content/comp.CompTest/comp.TestFolder/comp.kkp_test
rdesc=test

user=USER1




Any ideas?