Hi @lalajee
From the screenshot it seems you migrated from old version Exchange (Exchange 2010 or older) to Exchange 2016 and there are some old OABs and associated public folders left.
If you no longer need these entries, you can try deleting them from Active Directory Users and Computers (ADUC) if you can find them under the path in the message.
Besides, to me since this is a warning message rather than an error message, which indicates some of the entries failed to be updated when updating global address list, you can also ignore it.
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