Your storage may not be set up.
Recording only works after storage is set up.
You may not have the rights to watch recordings.
Log in as administrator and check the permission at Settings > Permissions > [group name] > Permissions > Record viewing. If you don't have access to these settings, ask your administrator for the permission.
You may need another user to authorize your access to recordings.
If dual authorization is in use, you'll need another dual authorizing user to open the lock to access recordings.
Your disk may be faulty.
Check your disks for faults. After replacing the faulty disk you may need to regenerate database for the recordings.