Opening calendar window does not work

[UnitedMarsupials-zz]

I installed the Lightbird-extension and restarted SeaMonkey. I see the new "Calendar" menu-entry under "Windows" menu and the fifth icon for same in the lower-left corner of the every SeaMonkey window.
However, when I press on any of the above, I get a popup-window (without title) with the following content:

XML Parsing Error: undefined entity
Location: chrome://lightbird/content/sunbird/calendar.xul
Line Number 53, Column 1:

<window id="calendar-window"
^

Here is the window-shot of it:

I'm using SeaMonkey-2.46 built with Lightning enabled -- although I do not know, how to access the extension now (and was hoping, Lightbird will help).

[alice-mkh]

You have to enable Lightning from addon manager. Regardless of whether Lightbird is installed. :)

[UnitedMarsupials-zz]

Should not Lightbird tell me about that?..

[alice-mkh]

I don't think it can even detect that.

[alice-mkh]

And either way, that's usually an obvious thing: if an extension depends on another one, the another one should be enabled. Installed but disabled is basically the same thing as not installed at all from SeaMonkey's viewpoint.

[UnitedMarsupials-zz]

I'm staring at my SeaMonkey running and do not know, whether Lightning is enabled/installed. Having searched online, I found your extension... I do not know the available API, but would expect an extension to be able to learn, whether or not another extension is available...

[alice-mkh]

Open addon manager, and you can see it there.

[UnitedMarsupials-zz]

Thank you, I appreciate your help. The Lightning is not mentioned in the Add On manager -- it used to "just work" before (and integrated with Google Calendar even), but disappeared after an upgrade recently:

[alice-mkh]

And the problem is that if Lightning isn't there, Lightbird window won't load (like on your screenshot), and the scripts won't have a chance to be executed, so I cannot show anything there.
I don't control that error window, it's what SeaMonkey shows if there's a syntax error, or an undefined entity (translation) etc.

[alice-mkh]

Thank you, I appreciate your help. The Lightning is not mentioned in the Add On manager -- it used to "just work" before (and integrated with Google Calendar even), but disappeared after an upgrade recently:

So it's not even installed. Install it. :)

[alice-mkh]

What SM version do you have?

[UnitedMarsupials-zz]

Do you not get a chance to run something at the install-time -- to detect Lightning presence?
My SM-version is 2.46, built from source using FreeBSD port with the same options as before -- including the --enable-calendar option. I'm trying to investigate, why the extension did not get built -- which is a possible bug in the port, but Lightbird ought to be able to detect such a problem...

[alice-mkh]

https://addons.mozilla.org/en-US/seamonkey/addon/lightning/versions/beta
Version 5.1b1 from there works with 2.46, but I don't know if it even exists for FreeBSD.

And no, I don't get a change to run anything on installation. Restartless extensions can do that, but the traditional ones can't, as the overlays are only loaded when SeaMonkey starts up.