Since Firefox/Thunderbird 40 (SeaMonkey too), users without language packs installed are prone to encounter an apparent issue while installing their first language pack. To reproduce it:
In the (empty) Languages pane of the Add-ons Manager, click in "Get more languages packs...". A new tab is open.
Install one or more language packs from the displayed webpage.
Go back to the tab with the Add-ons Manager.
Here, the entries for the new language packs seems broken, but, actually, they are fine: refreshing the page fixes the view. It's a regression bug in the Add-ons Manager itself:
https://bugzilla.mozilla.org/show_bug.cgi?id=1194927
Adding a workaround from the add-on itself seems a bit tricky, so I will wait the upstream fix.
Since Firefox/Thunderbird 40 (SeaMonkey too), users without language packs installed are prone to encounter an apparent issue while installing their first language pack. To reproduce it:
Here, the entries for the new language packs seems broken, but, actually, they are fine: refreshing the page fixes the view. It's a regression bug in the Add-ons Manager itself: https://bugzilla.mozilla.org/show_bug.cgi?id=1194927
Adding a workaround from the add-on itself seems a bit tricky, so I will wait the upstream fix.