Hello DavidJenkins
This usually happens when you have forwarded events and the amount of information received is too large.
Please check the next articles which includes corrective actions:
https://learn.microsoft.com/en-us/answers/questions/150358/event-id-111.html
https://social.technet.microsoft.com/Forums/windowsserver/en-US/93cd6c41-c502-48bc-9db7-077405fff829/error-from-event-log-forwarding-setup-the-description-for-event-id-111-from-source?forum=winserverManagement
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