"You must specify a time"

Feb 28 at 9:18 AM
I am trying to sync from Google Calendar to Outlook and get this instead:

Sync started at 28-Feb-17 11:13:41
Syncing from 20-Feb-17 to 17-Sep-17

Outlook ← Google

Reading Outlook Calendar Entries...

9 Outlook calendar entries found.

Reading Google Calendar Entries...

52 Google calendar entries found.

Total inc. recurring items spanning sync date range...
ERROR: Failed to retrieve Google event
The following error was encountered during sync:-
You must specify a time.
Operation aborted after 1 failed attempts!

What does "you must specify a time" mean?

Thanks in advance.