[Evolution-users] Calendar :: Modify CalDAV communication to JSON

[Matthias Kuntze]

Am Mittwoch, dem 22.04.2026 um 11:03 +0200 schrieb Milan Crha via
evolution-users:
> ... the server is supposed to return XML, not JSON. No idea why
> they changed it, but from my point of view it should not be changed,
> also because there is no JSON in the RFC 4791 [1].

As I use flatpak, I did the following:
   $ flatpak run --command=sh org.gnome.Evolution 
   [📦 org.gnome.Evolution Downloads]$ CALDAV_DEBUG=1
   /app/libexec/evolution-calendar-factory -w >& logfile &
   [📦 org.gnome.Evolution Downloads]$ evolution &
   [📦 org.gnome.Evolution Downloads]$ exit
   exit
   $ 
> ... Maybe they are trying to report some error/problem.

I got no error messages except that nearly each answer has been marked
as "< Content-Type: application/json" although the response came as
normal xml formatted text. It seems that a lot of email clients are
ignoring the Content-Type information and only evolution is correctly
throwing that error message. 
The provider (t-online.de in Germany) does not see an error at their
system as Windows, Apple and Android is able to work with that
situation (does not show an error).

What can be done now - except not using this provider?

Bye, Matthias