bug#51815: 27.2; Strange interaction between Org and Diary

[Eli Zaretskii]

> From: Robert Thorpe <rt@robertthorpeconsulting.com>
> Date: Sat, 13 Nov 2021 19:16:16 +0000
> 
> I use Org mode but I also use the normal calendar and diary.
> 
> This has an unwanted effect if I open an org file.  After org has been
> started the calendar no longer functions as expected.  If I press "i d"
> then it fails to insert an entry in the diary file.  A warning in
> *Messages* says:
> 
> "command-execute: Wrong type argument: commandp, org-agenda-diary-entry"
> 
> I don't use org-agenda, BTW.
> 
> To clarify there are two conditions that are needed to see this
> behaviour.
> 
> 1) Org-mode has been started in the Emacs session.
> 
> It does not happen if org-mode hasn't been started (e.g. by opening an
> org file in another buffer).
> 
> 2) Org-mode must be started first before calendar.
> 
> If calendar is started first and org-mode is started second then the
> calendar works.

Which version of Org are you using? the one that came with Emacs 27.2
or something else?