browser-plugins-npapi-3.0-alt1
(and epiphany-2.26.3-alt1)

I have apt-get installed gnash and mozilla-plugin-gnash, as a result, browser-plugins-npapi have been upgraded. And it has a new path for the plugins. But the older release of epiphany (and all other installed browsers) was kept. And now epiphany doesn't see the gnash plugin:

$ strace -e trace=file -fF epiphany 2>&1 | fgrep -i gnash
$ 

For correct upgrades, the older release of epiphany (and other relevant browsers) should be forced to be formally incompatible (according to the dependenies) with the new browser-plugins-npapi package, i.e., browser-plugins-npapi should have:

Conflicts: epiphany < 2.26.3-alt2

(2.26.3-alt2 updates the path in the 5.1 branch -- http://sisyphus.ru/ru/srpm/Branch51/epiphany/changelog , as for Sisyphus, the problem might go away in the next release because it is built with webkit.)