missing contacts, hotmail.com Exchange account, Active Directory error

My hotmail account has been migrated to Microsoft Exchange, so I have recreated my eM Client account as type Exchange.

In eM Client, my email and calendar entries are present, but my contacts are missing.  They are all present in Outlook.com, Windows 10 Mail, and iOS on my iPhone.

Menu -> Tools -> Operations -> Errors shows repeated error messages like this:

An error occurred
Synchronizing folder ‘MYNAME@hotmail.com/Contacts/’ failed due to the following
error: Invalid data source operation., There was a problem accessing Active Directory.
Check your network connections and try again.

I have eM Client version 7.0.27943.0 (released October 21, 2016)

Hello Phil,
we have seen this error happen with certain Distribution lists.
We have not been able to pinpoint what exactly is wrong with them.
So, as a quick fix, re-making these will resolve the issue.
If you’d like to help us analyze the issue and hopefully work around it we’d appreciate if you forwarded these DLs to us (rust@emclient.com with a link to this forum thread).

Regards,
Olivia