can't backup 11.2.0.2 database after catalog upgrade to 11.2.0.4
You should be able to backup an 11.2.0.2 database using RMAN with an RMAN repository that is set to 11.2.0.4. There seems to be some invalid objects in your RMAN repository schema. You may want to try compiling all of the invalid objects in your RMAN repository to see if they become valid. This probably has nothing to do with you backing up an 11.2.0.2 database with an 11.2.0.4 RMAN repository.