I recently installed a new BE CAS server in a remote office. OWA works from the BE server, but if I try to log into a user using OWA from the front end, I get the following. I am currently going through another working BE sever to compare settings in CAS and IIS. This user was also migrated from 2003, and it looks like the EX address is still pointing to the old 2003 server. Any help would be appreciated. This is the detail of the error message I get from the FE OWA:
User host address: 10.1.1.251
EX Address: /o=ccarey/ou=Mail Migration/cn=Recipients/cn=lark
SMTP Address: email@example.com
OWA version: 14.2.298.4
Second CAS for proxy: https://mar.ZZZZ.XXX.com/owa
Exception type: Microsoft.Exchange.Clients.Owa.Core.OwaProxyException
Exception message: The proxy CAS failed to authenticate to the second CAS (it returned a 401)
No callstack available
Exception type: Microsoft.Exchange.Clients.Owa.Core.OwaAsyncOperationException
Exception message: ProxyPingRequest async operation failed
Exception type: System.Net.WebException
Exception message: The remote server returned an error: (401) Unauthorized.
Microsoft.Exchange.Clients.Owa.Core.ProxyUtilities.EndGetResponse(HttpWebRequest request, IAsyncResult asyncResult, Stopwatch requestClock)
Thank you for any assistance.