No error message is seen on the UI. The sync does not give expected results such as not creating archives for new accounts or disabling shared mailbox archives incorrectly etc.
The Tenant Name in Office 365 Sync configuration is misconfigured.
Configure a .onmicrosoft domain in the Office 365 Sync configuration as shown below and then run the sync to resolve the issue.

Please refer to the following article for more information.
Arctera Unified Platform Office 365 Sync gives unexpected results when the Tenant Name in configuration is misconfigured.