Data source element {1} is marked as read-only and it is mapped to the read-only Office property '{0}'. For read-only Office ...

Data source element {1} is marked as read-only and it is mapped to the read-only Office property '{0}'. For read-only Office properties, the values are generated by the Office applications; These values cannot be persisted to the data source, if you mark the data source element as read-only also.