Just found the related bug 57248 (metadata missing in templates on beta cluster). So that's not a new or unknown issue.

MediaViewer relies on [[commons:COM:MRD]]-style notation to parse template metadata. [[mw:Multimedia/Media_Viewer/Template_compatibility]] has some more information on how to make templates compatible.

(In reply to Lupo from comment #1)

Just found the related bug 57248 (metadata missing in templates on beta
cluster). So that's not a new or unknown issue.

That's an unrelated issue, probably caused by a failure to replicate remote file descriptions on the beta cluster. Also, it seems to have been fixed by now.

• Bug 69545 has been marked as a duplicate of this bug. ***

Yeah it was one of my suggestions that there should be a planned campaign to stimulate the local communities to fix this before a full launch...

Apparently, it did not come to fruition, and we launched with what users interpret as broken views on top of the data. I don't think that was a good idea.

(In reply to Derk-Jan Hartman from comment #4)

Yeah it was one of my suggestions that there should be a planned campaign to
stimulate the local communities to fix this before a full launch...

Apparently, it did not come to fruition, and we launched with what users
interpret as broken views on top of the data. I don't think that was a good
idea.

That's a pretty major goof.

Lesson to learn: do *not* deploy MediaViewer on a wiki unless the templates there have been updated accordingly!

Frankly said, no wonder many people at the de-WP community don't like this feature! (Well, it's probably only a small detail in the whole story, but details matter. And proposing re-use that violates the conditions of the license is really bad.)

In the future, engage the community early on (before deployment!) to get the templates updated. And if they don't co-operate, you'll have no choice but try to update them yourselves. Which, I fear, may now be the only way forward at de-WP. I image you might have a hard time finding admins there willing to do the work after that superprotect nonsense.

Software side, make MediaViewer not propose any re-use unless the license and author information is available. If MediaViewer doesn't have this information, it must not propose reuse outside of WMF projects. (I.e., no embeddable HTML etc.)

For no reuse without info see bug 69557.

Suggested fix posted here:
https://de.wikipedia.org/w/index.php?title=Wikipedia_Diskussion:Lizenzvorlagen_f%C3%BCr_Bilder&diff=133308165&oldid=132577906

We did some community outreach to address issues with local templates [1] (as early as November), but clearly not enough.

[1] e.g. https://lists.wikimedia.org/pipermail/wikitech-ambassadors/2013-November/000508.html

(In reply to Erik Moeller from comment #7)

Suggested fix posted here:
https://de.wikipedia.org/w/index.php?title=Wikipedia_Diskussion:
Lizenzvorlagen_f%C3%BCr_Bilder&diff=133308165&oldid=132577906

Erik: don't forget the license templates!

https://de.wikipedia.org/w/index.php?title=Wikipedia_Diskussion:Lizenzvorlagen_f%C3%BCr_Bilder&diff=133319428&oldid=133316289

Adapting the information-template is only a tiny part of fixing this.

Yep, I know (thanks for the prod, though); I sent Gergo the link to https://de.wikipedia.org/wiki/Kategorie:Vorlage:Lizenz_f%C3%BCr_Bilder earlier and he was going to take a look.

I'm building a JS/Gadget that will SHOW people what data is there, and can report errors, if stuff is broken

https://commons.wikimedia.org/wiki/User:TheDJ/datacheck.js

Early start, but hopefully that will make lack of machine readable data more visible to maintainers of files.

This is an excellent tool, Derk-Jan, thank you :-)

Some of the most common licensing templates on de.wp have been adapted (thank you to User:Umherirrender), so https://de.wikipedia.org/wiki/Olympiastadion_Athen#mediaviewer/Datei:2014_-_Olympic_Stadium_(Athens).JPG renders with full licensing visibility now.