If it is easier for you, the French forums are at http://www.opera-fr.com/forums/
My French isn't great, but I think you are asking about Speed dial groups? The only way to create a new speed dial group is to drop one icon on top of another - in that sense, it might be better to think of them as stacks rather than groups.
edit: i just realized that you're running jessie. for a system in a "testing" state i'd suppose a problem with fontconfig rather than one with openbox or opera. maybe a look at bugs.debian.org will reveal something of relevance to your problem.
@quaxeros: NPAPI is deprecated, all major browser vendors seem to be following this route, not least because of security issues with this old technology. Java itself has been the source of many such issues. So, we will not be adding back support for it. In fact Chromium upstream is planning to remove it from Windows and Mac and we will likely do the same.
Perhaps Oracle can make a Pepper plugin if not, you can use another browser for managing such servers. I would obviously suggest keeping Opera 12.16 for this on Linux. It doesn't have to be your main browser. You can consider 12.16 your "managing server" application and continue to use 26+ for everything else.
The easiest way to install both alongside each other is to use the tar package to install 12.16 as it places Opera in /usr/local so there will be no clashing paths.
Would it not be a good idea to develop a NPAPI plugin interface for Opera?
It is not trivial to do if you use Aura for your interface, which we do. Chromium for Linux used to have NPAPI support and dropped it when they switched to Aura.
It could be done but it is not worth the effort. All the browsers are now moving away from NPAPI. We will eventually stop support for it on Opera for Windows and Mac as well.
It is Oracle who needs to catch up with the real world. There have already been enough security problems with NPAPI Java, already.
I cannot live with a browser unfit for bank transactions.
Well, the repo is back for now, and they updated the Opera 12.16.x (a.k.a. "the Legacy version").
So please advise the new build number for the 12.16 version which you say has been updated. I still have build 1860 and checking for updates via the browser Help menu does not indicate a new version.
I have 12.16 installed to /usr/local/bin/ which means the package manager will not show 12.16 as installed and hence it will not be updated with apt. ( I suppose 26 installed to /usr/bin/ will update normally with apt).