OABGen encountered an error while generating the %1 file for version 2 and 3 differential downloads of address list '%2'. ...

OABGen encountered an error while generating the %1 file for version 2 and 3 differential downloads of address list '%2'.  The offline address book has not been updated so clients will not be able to download the current set of changes.  Check other logged events to find the cause of this error.

If the cause of the problem was intentional or cannot be resolved, OABGen can be forced to post a full offline address book by creating the DWORD registry key 'HKEY_LOCAL_MACHINE\%3\%4' and setting it to 1 on this server.  When OABGen next generates the offline address book, clients will perform a full OAB download.  After that time, the registry key should be removed to prevent further full downloads.

- %5