Error processing personal DLs by CPUU. Error: "This group contains more members than are supported when using Microsoft Office Outlook 2007 Service Pack 1 or an earlier version.' of type 'One-off object'" (4259005)

When processing personal DLs by CPUU the following error is generated:

2/14/2020 8:05:06 AM 7348 [Trace] Preparing personal distribution list 'H - 2019 List' message for update.
2/14/2020 8:05:06 AM 7348 [Trace] Updating contact 'This group contains more members than are supported when using Microsoft Office Outlook 2007 Service Pack 1 or an earlier version.' of type 'One-off object'.
2/14/2020 8:05:06 AM 7348 [Trace] Number of members in personal distribution list is '1'.

The DL is quite small and also Outlook used is not 2007 version.

The error is generated when CPUU attempting to process an old Exchange object (Distribution List). This is CPUU defect CPUU-1376.

To workaround the issue, please perform the following:

- copy DL to another DL, then delete the original object

-or-

- recreate the DL anew, adding members back, then delete the original one