Can you directly upgrade from Jetbackup 4 to Jetbackup 5?
This is not possible due to Jetbackup 5 using completely new systems. The following warning from the jetbackup documentation explains this:
"JetBackup 5 utilizes a new JetBackup Core and introduces a new Backup Structure and Engine. With that in mind, there will be NO DIRECT UPDATE from JetBackup 4 to JetBackup 5 and backups generated in JetBackup 4 ARE NOT COMPATIBLE with JetBackup 5."