Backup the database by run consolemigration.exe from <Arcserve install path>\Arcserve\Unified Data Protection\Management\BIN\Appliance ( https://documentation.arcserve.com/Arcserve-UDP/Available/8.0/ENU/Bookshelf_Files/HTML/ApplUG/Default.htm#Best_Practices_4_udp_cnsol_migrtn.htm?TocPath=Working%2520with%2520Arcserve%2520Appliance%257C_____9 )
Save the database backup on a network drive or flash drive.
Next uninstall just the console from Add / Remove Programs.
After uninstall, run the installer.
On the database part UNCHECK Overwrite existing database and continue with the installation
Once the installation is finished, try to access the the console again.