Hello Jonathan,
this is usually caused by either an issue during a Zimbra upgrade or when migrating/restoring a Zimbra install using the "/opt/ move" method without carefully following the instructions (e.g. trying to move Zimbra 6.0.10 files over a Zimbra 7.1.1 server)...
I suggest you to check the zmsetup.*.txt files in /opt/zimbra/log/ and the .install_history file in /opt/zimbra/, you might find some hints should the cause be an upgrade issue.
Just to verify which version you are actually running, could you please enter the following string in your Zimbra Web Client's search bar and paste the output here?
Have a nice day,
Cine
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