ESX Server 3.0.x Host Is Unable to Use VCB License from VMware Infrastructure Foundation License File
Details
If you configure an ESX Server 3.0.x host to use a VMware Infrastructure Foundation license file (released with ESX Server 3 version 3.5), the host cannot use the VMware Consolidated Backup (VCB) license.
Solution
To use VCB, upgrade the host to ESX Server 3 version 3.5.