Dispatch Outlook in Safe Mode to check for issues that are brought about by add-ins.
Stage 1: In Outlook, go to File > Option and select the Add-ins tab.
Stage 2: Click in a hurry button; another spring up discourse box will open.
Stage 3: Disable each module in turn.
Read more here:- https://www.datarecovo.com/fix-outlook-not-implemented-error/