When restoring image files with Image Explorer, the base backup file can't be deleted

Details

When restoring File Backup image files with Image Explorer, the base backup file cannot be deleted—even if you try to delete it manually or it becomes the oldest file and exceeds the set limit for image sets.

Example:
When a backup task runs on a set schedule, the following files are created: 

Base File 　 img_XXX_b00001.afb
Incremental File　　img_XXX_b00001_i00001.afb
Incremental File　　img_XXX_b00001_i00002.afb

Double-click on any of the files above and drag & drop a file to restore. This opens the base backup file (img_XXX_b00001.afb) in Explorer, but cannot be deleted.

This issue did not occur with Volume Backup image files—the base backup file could be deleted as expected. 

Causes

Under investigation.

Workaround

Sign out and log in again. After that, the undeletable File Backup image files can be deleted manually or automatically based on the Retention Policy.

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