I have windows server 2016 and was using exchange 2013 and about a year ago migrated to office365
Since then I have copied several users not sure why I am encountering this issue now (probably due to windows updates) as from what I read it seems to be related to exchange.
According to the following site https://www.vspbreda.nl/nl/ms-office/office-365/name-reference-invalid/ it has to do with the Default Global Address List and when I try and remove it on a test user I am getting an error.
Any ideas? also will it affect anything from my setup or is it safe to remove? TIA