The following event may be seen in the Enterprise Vault Event Viewer log:
Event ID: 41481 The User 'EV\VSA' attempted to restore a file item 'NewFile.docx'. The request has failed due to an unspecified error.|Item being restored:|SavesetID: #12932$180C00E245D10D84EB725CD93D75A46BF1110000EVSERVER1|Please check storage server event log for more details.
A Dtrace of w3wp on the EV server will show the following access error:
(w3wp) <232> EV:L {CFolderPermSyncWrapper::GetClientIdentity} (Entry)
(w3wp) <232> EV:H {CClientAuthenticate::RegisterClientIdentity} Error [Access is denied. (0x80070005)]
(w3wp) <232> EV:M CA : Com Exception HRESULT 0x80070005
The issue is due to different authentication used when using Search from within the VAC vs. from within a browser.
Open Enterprise Vault Search from a browser and perform the operation to restore the file to the original location.