"Cannot create the folder. You do not have permission to perform this Enterprise Vault operation."
The creation of folders in Virtual Vault is controlled by the Desktop policy settings Users can archive items and Users can reorganize items. If these are set to No then the user will not be able to create new folders in their Virtual Vault.
A Client Trace will show the settings applied to the mailbox in the format:
VVALLOWARCHIVE = 0
VVALLOWREORG = 0
Where:
VVALLOWARCHIVE relates to Users can archive items
VVALLOWREORG relates to Users can reorganize items
Unable to create a folder in Virtual Vault.