Multiple EUM addresses in proxyAddresses field is detected for the user %1. A user can have at most one EUM address in proxyAddresses ...

Multiple EUM addresses in proxyAddresses field is detected for the user %1. A user can have at most one EUM address in proxyAddresses field. EUM address of this user will not be replicated until this problem is fixed.
Resolution:
Delete extra EUM addresses in proxyAddresses field in AD for this user.