still no answer (sunday lovley sunday :) )
soo i patch the version to a newer version,but still when trying to upgrade to 5.2,same error:
ClearPass Policy Manager 5.1.1.41874 on CP-HW-25K platform
pgrading from image file=CPPM-x86_64-5.2.0.43003-upgrade.bin
Extracting image...
INFO - Backing up current config...
INFO - Starting backup. This may take some time...
INFO - Backup databases for Insight
INFO - Backup databases for AppPlatform
INFO - Backup databases for PolicyManager
ERROR - Error creating backup file
ERROR - Backup failed
ERROR - Backup current config failed
ERROR - Exception performing upgrade: Pre-install task=10-backup-config failed
ERROR - Upgrade failed