Symptoms:

• You configure a backup plan with Plesk/Cpanel extension
• The backup plan is configured with file-filters in it and is working correctly
• You try to mount the created backup from the Plesk/Cpanel management console
• Mounting fails with the error message "failed to mount the recovery point"

Cause

If file-filters/exclusions are used in the backup plan, then complex logic is performed based on using the search for occupied sectors for included/excluded files. 
These algorithms check all the data in the recovery point and compare it with the filter. The process may take considerable time if the amount of excluded/included data is big compared to the total amount of data on the machine, so the process fails due to the timeout. In the latest builds, it is possible to increase the timeout but still, it may not be enough to browse the data.

Workaround

As a workaround, you can avoid using exclusions by separating the data that you need to back up from the data that you don't need to back up. Recommended solution is to partition disks into volumes (e.g. LVM) and move the data that you do not need to back up to a separate partition. When done, create a new backup plan and select only those partitions that you need to backup. The new backup plan should be disk/volume level backup, file-level backups cannot be mounted. Make sure that the backup plan is configured according to the user guide: see Acronis Cyber Backup extension for Plesk 13.2 Configuring a backup plan for a Plesk server