Event Message:

DNS server wrote new version of zone name , to file filename. The data is the new version number.

Source Event Log Event ID Event Type
DNS System 850 Information

Explanation:

The specified database file on the primary server has been updated. Changes have been made to the resource records or new records have been added to the database. The serial number in the SOA record has been incremented by one.

User Action:

To view the latest version number, open Event Viewer and double-click event ID 850 in the system log. The version number is displayed in the Data section of the Event Details dialog box.