@Terri-Lynn Levesque Thank you for reaching out to us, As I understand you have received an email mentioning about the error reported from Azure AD Connect tool while synchronizing objects from AD, the same email will have the information about the issue which is being reported.
Just wanted to check if you can share more details from the email (kind of issue which is reported) or you can review the same in Azure AD portal as well, reference: https://zcusa.951200.xyz/en-us/azure/active-directory/hybrid/connect/tshoot-connect-sync-errors
Let me know if you have any further questions, feel free to post back so that we can work on the issue that you are facing during synchronization.