"ServiceUnknown" D-Bus error in Flatpak
From https://github.com/flathub/org.gnome.Evince/issues/12
When opening a file in the Flatpaked evince, you'd get:
Error registering document: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: org.freedesktop.DBus.Error.ServiceUnknown
But the evince UI can't start this service as it's not available on the bus, and can't be autostarted because our D-Bus proxy thinks that it's a different application.
68 #define APPLICATION_NAME "org.gnome.Evince"•
72 #define EVINCE_DAEMON_SERVICE "org.gnome.evince.Daemon"•
Changing the daemon name to org.gnome.Evince.Daemon
should fix it.