The OAB url can be accessed through IE and Chrome without problems (authentication pop-up).It happens to all users on all kinds of devices, so this is not isolated. The strange part here is that external OutlookAnywhere clients can download the OAB just fine, so this seems to be related to NTLM or Kerberos in some way. Both servers are running Exchange 2013 CU6.īITSadmin show the jobs failing with the error code 0x80190191: HTTP 401 The two Exchange servers in question are load-balanced by a KEMP cluster, with HTTPS round-robin (SSL termination is done at the Exchange servers, no caching or any of the sort). They get stuck forever on 'Offline Address Book is connecting to Microsoft Exchange'. We're having difficulties with Outlook clients running in cached mode.
