To resolve this issue, grant the specified user access to the media server's Backup Exec Database (BEDB). This can be done using the Backup Exec Utility.  The Backup Exec Utility can be launched by running the beutility.exe located by default in the following directory:

C:\Program Files\Symantec\Backup Exec\ 

After the utility is running, the database access can be granted by performing the following steps:

1. Select a media server from either a media server group or from the All Media Servers subnode.
2. On the task pane, under Database Tasks, click Change Database Access.
3. In the User Name field, enter the user name.
4. In the Domain field, enter the user's domain.
5. Select Grant access.  (Figure 1)

Figure 1
 

6. Click OK.
7. After the operation finishes, click Close on the Operation Progress screen. 
8.Run the setup of Backup Exec again.