Since the update two days ago, Amazon Prime Videos do not play anymore in Firefox, which reports a "crash of a plugin "" " with a yellow banner at the top of the page. It is obviously the Widevine plugin, as the website complains about this plugin as missing. And dmesg delivers a segfault message:

[ 551.104884] MainThread[3295]: segfault at 0 ip 00007f2fb43d4bf9 sp 00007ffcc1fe94a8 error 6 in libxul.so[7f2fb4346000+492e000]
[ 551.104890] Code: 92 06 48 8d 0d 28 8d cc 04 48 89 08 c7 04 25 00 00 00 00 00 00 00 00 0f 0b 48 8b 05 89 12 92 06 48 8d 0d d2 8c cc 04 48 89 08 <c7> 04 25 00 00 00 00 00 00 00 00 0f 0b 48 8b 05 6b 12 92 06 48 8d