We recently ran across a problem where users trying to log on to Microsoft Office Outlook Web Access in Exchange Server 2007 would receive the following error message:
"A problem occurred while trying to use your mailbox. Please contact technical support for your organization."

If Show Details is clicked in this error message, a call stack including the following message appears:
"Exception message: Property Languages cannot be set on this object because it requires the object to have version 0.1 (8.0.535.0) or later. Current version of the object is 0.0 (6.5.6500.0)." [more]

After some research we found that this issue occurs when the msExchVersion attribute is not set correctly on the user object in the Active Directory. Exchange 2007 uses the msExchVersion attribute to determine the version of Exchange that user objects are associated with. If the version value is less than 0.1, Exchange 2007 considers the object "read-only" and cannot write changes to the object.

The msExchVersion attribute may not set correctly if you created the user's mailbox by using the Active Directory Users and Computers Microsoft Management Console (MMC) snap-in instead of by using the Exchange 2007 Management Console, as was the case in this situation. 

To resolve this issue, type the following command at the Exchange Management Shell prompt:
Set-Mailbox User_Name -ApplyMandatoryProperties

To verify the msExchVersion attribute, type the following command at the Exchange Management Shell prompt:
Get-Mailbox User_Name | format-list ExchangeVersion