"Duplicate File Load Detected

I have this error when logging in/reloading:

Message: Interface/AddOns/MailBookKeeper/embeds.xml:13 Duplicate File Load Detected. [Interface/AddOns/MailBookKeeper/Libs/AceEvent-3.0/AceEvent-3.0.xml] first loaded at [Interface/AddOns/MailBookKeeper/embeds.xml:11]
Time: Sun May 19 20:12:12 2024
Count: 2

Any way to fix it?