Unable to create the deduplication disk storage.
An error occurred while creating deduplication disk storage.

Or Pdde-Config.log reports the following error -
Fri 07/22/2022 2:06:01.17 Setting ocsd service to start on demand...
[SC] OpenService FAILED 1060:
The specified service does not exist as an installed service.
Fri 07/22/2022 2:06:01.21 ERR: Service Controller call 'sc config ocsd start= demand' failed: 1060
Fri 07/22/2022 2:06:01.22 An error has occured while attempting to configure. Aborting...
Fri 07/22/2022 2:06:01.22 Stopping services...
Fri 07/22/2022 2:06:01.22 Stopping spoold service...
Warning: 2: __openReader: could not open file R:\BackupExecDeduplicationStorageFolder\etc\puredisk\contentrouter.cfg
Stopping service spoold: done
Fri 07/22/2022 2:06:01.30 Stopping spad service...
Stopping service spad: done
Fri 07/22/2022 2:06:01.38 Stopping ocsd service...
{"level":"debug","Key:":"SOFTWARE\\VERITAS\\NetBackup\\CurrentVersion","error":"The system cannot find the file specified.","time":"2022-07-22T02:06:01-04:00","message":"not found"}
Command : [stop]
Service Name : [ocsd]
Failed to stop ocsd.
Error: [The specified service does not exist as an installed service.]
Backup Exec Open Cloud Storage Daemon service not found on the Backup Exec server.
A new service named "Backup Exec Cloud Storage Daemon" got introduced with Backup Exec 21.3. It is responsible for sending data to cloud deduplication storage folder.
If the service is not found in services.msc run a repair Installation of Backup Exec.
Configure Deduplication Storage if the service starts to appears in services.msc after the repair installation and dedupe configuration should work at this point.
If the repair installation is not helpful, upgrade to Backup Exec 22.2 or later. After upgrading, configure Deduplication Storage. Or uninstall Backup Exec 21.4 once and reinstall Backup Exec 21.4 enabling Deduplication feature. After reinstalling, configure Deduplication Storage.