After an upgrade or installation of Enterprise Vault version 8 Vault Cache does not download any data for one or more Enterprise Vault Servers. A Full Client Trace (see technote linked at the bottom of this technote on how to run a client trace)

A review of the client trace will show the following.

HDR: Requesting URL:http://EVSERVER/EnterpriseVault/ListArchives.aspx
HDR: ~EVServerConnection::Get
HDR:SYNC: Invalid MDCSyncResponse: Root missing
HDR:SYNC: ~MDC::ServerResponseHandling::Request: 0x80004005
HDR:SYNC: ~MetaDataCacheScheduler::GetAccessibleArchives: 0x0
HDR:SYNC: ~MetaDataCacheScheduler::UpdateMDCArchiveMapping
HDR:SYNC: Error (COM) synchronizing: 0x80004005
HDR:SYNC: Failed
HDR:SYNC: MetaDataCacheScheduler::UpdateSyncTimes

The request in IIS logs will reveal a 500 error for the request (internal server error)

Attempting to access the URL directly (http://EVSERVER/EnterpriseVault/ListArchives.aspx) will show the error "Error in Application" the following from a client PC.

1. On the Enterprise Vault Server open IIS Manager.
    
2. Navigate to the EnterpriseVault virtual directory and open the properties of this.
    
3. On the ASP.NET tab change the version from 1.1.4322 to 2.0.50727 or above.
    
4. From Command Prompt issue IISRESET command.
    
5. From client PC clear the Temporary Internet Files from Internet Explorer and test Vault Cache again.