You need to uninstall it and reinstall the browser. I had this happen too.

Actually, I've been trying to do that this morning, in the hope I could revert to an older version which would work. But I can't even find out how to uninstall things! None of the settings screens are giving me the option to do that. There must be a straightforward way to do this, which would be easy on my desktop, but I can't find it.

I too have had exactly this problem today. I run an A500 tablet on Android 4.0.3. Its old but firefox always ran fine until today. I checked the firefox version=53.0. So I uninstalled it, went to Play Store and downloaded FF. V53.0 came down and installed without error and I am back to the error msg quoted above. Any ideas? My wife cant order stuff!!!

Oh. So, even if I'd managed to find out how to uninstall it, I would still be having the problem. Now I'm also feeling somewhat cheesed off that several of us seem to be having this problem and we're out on our own here. Can't Mozilla help? I'm reluctant to check with Android in case this is all part of G*****'s world domination plan...

Almost 100% certain its not an Android problem and I have confidence Mozilla support will sort it. It must be tricky to check every FF change against every version of Android out there. The FF check to see if its running on a supported OS must have a very simple to fix buglet esp. as the error msg erroneously indicates it thinks it running Arm architecture. Your tablet might have its original browser still available for use till the problem gets fixed. ps My wife says the error msg started yesterday evening not today. If I get time I might try installing FF 52

You obviously understand more than me about the error message. You're right, I can still use the original browser, up to a point - I downloaded Firefox when the browser couldn't cope with various tasks, so it has its limitations. I'll be interested to hear how you get on with installing FF52.

Is your device a Galaxy Tab 2? Firefox 53 requires a CPU feature that is called NEON which significantly improves media playback. The Galaxy Tab 2 is the most common device affected by this change.

No, it's an Asus SL101 - I know, hardly the most up-to-date piece of technology, but it's a serviceable thing.

Asus SL101 also uses the Tegra 2 CPU and thus is not compatible with Firefox 53.

well as expected reverting to firefox 52 got rid of the problem. I have also altered google play so it doesnt auto update back to 53 again. Pity it just updates and breaks FF without warning + gives a msg indicating I have downloaded the wrong version ! Looking at bug info It looks as though this wont be fixed so its either go back to 52 and stop updates, move to another browser, or junk your tablet

Thanks for all the advice here. oldchap's response above confirms my fears. I can't afford to replace the tablet at present so I'll have another go at reverting to FF52 if possible.

Finally managed to uninstall FF53, but FF won't let me reinstall an older version. Further investigations on this site, via my old browser on the tablet, have shown lots of people cheesed off with FF53, some for the same reason as me, some for several other reasons. Fingers crossed, it seems to be working OK here on the desktop, but I'm sorry to be bidding farewell on my tablet.

Once you've uninstalled FF53, google for firefox 52 APK and download that, then install it. I think I got FF52 from <strike>http://www. androidapksfree.com/ apk/firefox-apk-for-android-latest-version-download/</strike> once I had avoided all the adverts in other places. (scroll down to see the older versions). Uninstalling FF kept my favourites etc. Check FF52 works ok, then goto Play Store and set it to stop updates (It will stop all updates which doesnt matter too much on old Tablets if you ignore the lack security updates! My wife has confirmed FF52 is fine..it must be as she has resumed ordering stuff.

No need to go to some random unofficial download site to get previous versions as you can get them at say https://archive.mozilla.org/pub/mobile/releases/ if you must.

I was hopeful that James's reply would solve this and fell to seeking the option he suggests. Alas, it's taken me way beyond my level of technical competence - I have simply no idea what to do with the array of files and blocks of code presented to me in the archive. I'm also conscious of how much time this has already taken, and resentful that Mozilla didn't give me the option of checking more truthfully whether the update would work on my tablet and therefore the option of retaining the previous version that was working just fine. So the ultimate result is just making me think 'Bye-bye Firefox'. Grrr.

https://archive.mozilla.org/pub/mobile/releases/52.0.2/android-api-15/multi/

It should not update anymore to the incompatible version. There was a setting on the Play store that was allowing those tablets to upgrade.

Yay! At last. Many thanks to everyone for help. I've now got a version of an age which clearly suits the age of my tablet, so all is not lost and I no longer despair of Mozilla!

I spoke too soon. Went this morning, full of cheer, to open up yesterday's succcessful download, and - guess what? - just got the message that Firefox no longer supported this version on Android. That would be fine - all I needed was the version that used to work perfectly OK. I really, really am going to give up now. But thanks again to everyone who has aimed to help. It's not your fault.

In my case, it's not so easy to simply give up FF on my Samsung GT-P7300 with Android 4.0.4 because I had it synch'd to the FFs I use both on on my Linux Ubunto and on my Android Lollipop. Isn't there a case for asking for FF53 to be made backward compatible to accommodate those of us with older tablets? Aren't we in this thread identifying a design drop-off in FF53 that needs to be corrected? Or what about introducing this backward compatibility in a new FF54?

As per my earlier entry above, I downloaded the last version of FF that worked, stopped the tablet updating apps/programs so you dont finish up with the same problem again, and we have been ok ever since. Also if your tablet is anything like ours, we dont need updates to all the stuff we've had on it for ages and dont use so its now a little faster as it does have to keep downloading and updating