https://www.reddit.com/r/synology/comme ... ng_active/To delete specific backup versions in Active Backup For Business
Open Active Backup for Business on the Synology device
Click "PC/MAC" (i.e. for that type of backup or other type as appropriate)
Click "Task List"
Click the Task Name that has the backup you want to delete
Click "Version"
Hover your mouse over the line with the specific version you want to delete and a trash can icon will appear on the right hand side
Click the trash can icon
In the "Are you sure ..." pop-up, click Delete