Client Access server "%1", running Exchange version "%2", is proxying Outlook Web App traffic to Client Access server "%3", ...

Client Access server "%1", running Exchange version "%2",  is proxying Outlook Web App traffic to Client Access server "%3", which runs Exchange version "%4". To ensure reliable interoperability, the proxying Client Access server needs to be running a newer version of Exchange than the Client Access server it is proxying to. If the proxying Client Access server is running a newer version of Exchange than the Client Access server it is proxying to, the proxying Client Access server needs to have an Outlook Web App resource folder (for example, ")\ClientAccess\owa\8.0.498.0" that contains all the same versioned resource files as the Client Access server it is proxying to. If you will be running Outlook Web App proxying with mismatched server versions, you can manually copy this resource folder to the proxying Client Access server. After you copy this resource folder to the proxying Client Access server, you need to restart IIS before proxying will work.

Client Access server "%1" tried to proxy Outlook Web App traffic to Client Access server "%2". This failed because the Outlook ... Client Access server "%1" tried to proxy Outlook Web App traffic to Client Access server "%2". This failed because the Outlook ... Client Access server "%1" tried to proxy Outlook Web App traffic to Client Access server "%2". This failed for user "%3" ... Client Access server "%1" tried to proxy Outlook Web App traffic to Client Access server "%2". This failed for user "%3" ... Client Access server "%1", running Exchange version "%2", is proxying Outlook Web App traffic to Client Access server "%3", ... Client Access server "%1", running Exchange version "%2", is proxying Outlook Web App traffic to Client Access server "%3", ... Client Access server %1 failed to obtain site information for %2 because Client Access server %2 isn't contained within an ... Client Access server %1 failed to obtain site information for %2 because Client Access server %2 isn't contained within an ... Client Access server %1 failed to proxy Exchange Web Services to Active Directory site %2 because none of the Client Access ...