This is a new error I believe with Mac and Outlook 2016. There was a problem and Office365ServiceV2 was closed
I had a client call in with this issue and since Outlook 2016 on Mac is so new, there was not much on the internet about it that wasn’t extremely challenging (even for me) , so I recommended to my client to uninstall/reboot/reinstall the Office program and see if that helped.
He reported the error has not come back.
Try it, might work for you and I hope it goes. The Apple discussions give very complicated repair/fixes.
If you are a technician, you might find my training videos helpful!
