We have upgraded from 6.3 SP1 to 7.3 PRPC. The new version installed in Jboss 6.4 AS and Oracle DB.
We have set 5MB upload limit while adding attachment. When user uploads a file >5MB size, an 413 alert is coming with some response from Jboss which can't be closed anyway. There is a solution given in below article but doesn't resolve our issue.