During online restore after the backup is selected and clicking Next, the error "Access is denied" can occur, even though the user account under which the restore is being performed has all necessary permissions.
This will happen if the path where the unpacked backups will be stored is not a folder but the root drive.
1. Create the folder for unpacked backups to be stored.
2. Right-click Recovery Manager for Active Directory in the console tree and select Settings | Unpacked Backup tab, then press the Browse button and navigate to the created folder.