The Address Book custom properties couldn't be parsed. Invalid file "%1" Line number = %2 Position = %3 Message = "%4" . ...

The Address Book custom properties couldn't be parsed. 

Invalid file "%1"  Line number = %2  Position = %3 Message = "%4"

. A valid custom property file format is required for Outlook Web App to  parse it and display the values to users. If this error isn't addressed, users won't be able to view the custom properties. The Help and Support Center provides information about troubleshooting this issue.

The Address Book custom properties couldn't be parsed. Invalid attribute count in "%1" at line number = "%2".Each CustomProperty ... The Address Book custom properties couldn't be parsed. Invalid attribute count in "%1" at line number = "%2".Each CustomProperty ... The Address Book custom properties couldn't be parsed. Invalid element found in "%1" at line number ="%2" position = "%3". ... The Address Book custom properties couldn't be parsed. Invalid element found in "%1" at line number ="%2" position = "%3". ... The Address Book custom properties couldn't be parsed. Invalid file "%1" Line number = %2 Position = %3 Message = "%4" . ... The Address Book custom properties couldn't be parsed. Invalid file "%1" Line number = %2 Position = %3 Message = "%4" . ... The Address Book custom properties couldn't be parsed. RootElementNotFound in "%1" at line number = "%2". Make sure that ... The Address Book custom properties couldn't be parsed. RootElementNotFound in "%1" at line number = "%2". Make sure that ... The address book functionality may not work correctly for Exchange Server 2007 Outlook Web Access clients with this version ...