Verify the following regarding the SharePoint server software on the NetBackup server or client:
SharePoint server software must be installed and operational.
For SharePoint 2010, the Microsoft .NET Framework 4.0 is installed on the SharePoint servers. For SharePoint 2007 and earlier, the Microsoft .NET Framework 3.5 is installed on the SharePoint servers.
When you use multiple front-end SharePoint servers, all front-end server Web sites must be uniformly identified in IIS. Identify the sites with either host headers or IP addresses, but not both. An environment that mixes host headers and IP addresses across multiple front-end servers is not supported.
To prevent restore failures, the IIS Default Application Pool identity must be a valid SharePoint user ID.
The SharePoint user should be an administrator user account.
More Information
NetBackup server and client software requirements for NetBackup for SharePoint Server