I switched to Pale Moon because this was happening with a lot of my plugins. It's much faster than Firefox on my computer, and uses less memory, so Pale Moon might be the way to go if other members are having issues. Unfortunately it only works on Windows & Linux.

I did a bit of checking and found that there is a Mac version of Pale Moon called New Moon.

I downloaded and installed it.

The good news is that it runs and supports Rikaisama seamlessly. At least the basic functions in J-E and Sanseido mode. Haven't got the audio working and haven't tested the direct-to-Anki function.

The bad news is that it is still in development. For example, while Pale Moon has a language pack which allows you to run the browser in Japanese (the translation is only partial apparently but would probably put the menus and such into Japanese), the current build of New Moon won't run it. It also froze temporarily (for a few seconds) a few times.

So I won't be switching to New Moon right now, but it is certainly something to bear in mind if it comes to the point where Rikaisama won't run on Firefox.

If anyone wants to try it out, here is the download link:

http://mac.softpedia.com/get/Internet-Ut...Moon.shtml

I was having the exact same problems that CureDolly had. I use Windows 7, Firefox 43.0.4 and Rikaisama 22.9. So far it is working again by disabling "whitelist required" and "signatures required" as CureDolly indicated.

I was having the same problems, but having upgraded FF to 43.0.4 and getting the latest MAC version of Rikaisama 22.9, it's stopped complaining and lets me use it again.

When you look at Rikaisama in your addons, do you no longer see the warning message?

When you look at Rikaisama in your addons, do you no longer see the warning message? I tried reinstalling after what you said and I am no longer getting it. Has something changed very recently I wonder? I had the warning all the time for weeks. Am tentatively re-enabling required signatures and whitelist.

I am not sure whether I ought to allow Firefox updates or not.

I haven't disabled anything, or messed about  with whitelists, but everything seems to be working fine. I'll post back if that changes over the next few days, but hopefully it's sorted now.

Quick update: I re-enabled "signatures required" and "whitelist required" and everything was fine for a while and then for no apparent reason Firefox went back to blocking Rikaisama and not allowing re-install. Currently I have whitelist and signatures disabled and auto-update disabled too as I am afraid a new update may mess things up entirely.

A friend, also on Mac installed Rikaisama normally last week and has had no problems so far. It seems a rather sporadic problem that some people are having on both Windows and OS X and other people aren't.