installing earlier versions of Firefox on Mac

[#1]

As per query on another thread - now have .dmg file for v27 Firefox.
Been having weird issues since last update to v28.
Decided I want to try going back to 27 instead of forward to 29. (Curiosity.)
Just checking if anyone has done this. Can I just overwrite v28 already installed or is best to remove old one first?
Only got couple of add-ons, can easy grab those again if necessary.

[#2]

you can just overwrite the existing file in applications.

[#3]

Thanks  
That was easy.
But didn't solve the problems (that seemed to arise since v28). So back to the drawing-board... 
Having to use Safari to look at iPlayer (or any BBC site), and few others.

[#4]

You could try Firefox ESR version. It has all the latest security updates but less of the 'bleeding edge' changes.
24.5.0 I think is the current one.
Linky here.

[#5]

Ah! Thanks  
I'll try it tomorrow.
Still be able to use Ghostery, etc., do you think? (I tried disabling add-ons earlier so it was not them causing the weirdness.)
edit - I have to go get this stuff via Safari. Can't get on Mozilla at all due to this problem 

[#6]

Yes you can use most of the current version add-ons. I just hope the problem is fixed by a change in version, rather than a problem inside your Firefox profile. 

[#7]

Yay! You did it again!
ESR worked 
Somewhat quicker, too. (Speeded onto this forum in a flash.) Check it out people!
So I can watch iPlayer again without having to fire-up Safari or some other.
Noticed a (paid-for) Firefox add-on while I was there.
https://addons.mozilla.org/en-US/firefox/addon/cck/
Says, among other things, you can disable about:config. Being a bit ignorant I'm wondering what would be the advantage of that?
Thanks, that was brilliant. I'll buy you a virtual drink 

[#8]

Virtually alcohol free please. 
That add-on would be useful for organisations who want to lock down the functions of a Firefox install. Not really useful for home users though, unless used in a parental situation, possibly. 

[#9]

There we go. That can be virtually anything you like in there. (I'm totally tea myself actually.)

                                §
                                /
                           ‘   /
            _________/
           (……………)
            \                 /__--z
            |                 {~~|ß
            |    †ea       |    /∫
            |                 |   /ƒ
            |                 {∞√
            |                 |  •
       __{---------------}__    
<<<<≤≤≤≤≤≤≤≤≥≥≥≥≥≥≥≥>>>

I'd be fascinated to know what's missing from the ESR version (that I'm not missing at all at the moment!).
And very pleased I don't have to go delving into the config file!  

[#10]

Oh well, that was short-lived  
Now cannot access iPlayer on Firefox of any kind, nor Safari. Even tried Dooble.
I notice that pesky 212.56.73.* IP cropping up on the firewall log again everytime I try iPlayer. What's up with that or why it might be causing problems I don't know, maybe the link is not working. Apparently its Google - why I'm unable to access BBC sites at all if there's a Google link issue is also a mystery, and an annoyance.
Tonight I'm fed up with internet, and the people who run it. I have a few words but I'll spare the mods the trouble of censoring them!

[#11]

So what is going wrong? The first thing in solving a problem is to find the reason. I'm not sure of the exact symptoms, so if you can lay things out without being too frustrated by it all, we can see if there's anything to be done. 

[#12]

Not feeling quite so angsty as I was the other night!
At stage now where, as you say, its a bit of a mystery.
Yes, do have something to work on now. - Previously there was just no response at all. Now I'm getting pages that look like they're missing their stylesheets.
So, iPlayer used to get Akamai IPs - 23.61* 23.62*, etc. That's stopped and its now 212.56.73.* (PN's weirdy google-cache thing).
Could this mean some of the content is getting shunted round Google servers instead of Akamai?
And that there's something going wrong with it?
Not knowledgable about these things so just guessing...

[#13]

What DNS servers are you using? Different DNS servers can give you differing results as to where the content (or CDN) connects from.

[#14]

No idea!
Just went through everything on the router pages, I can't find anything about that - apart from dynamic DNS, which is disabled.
It'll be whatever the default set-up was? I've never tinkered with it.

[#15]

Ok, probably PN's DNS servers then. As a temporary test add OpenDNS to the Mac. Go to Settings->Network and then either Airport or Ethernet. For Ethernet it's just the DNS tab but for Airport you click the Advanced button then DNS tab. Then click the plus button under the DNS list (which will be empty apart from the greyed out router IP address) and add 208.67.222.222 then add this one 208.67.220.220
Go back to the Network list and click the Apply button.
After that's been set try iPlayer out to see if it works correctly, just to check completely try on different browsers.
To remove those DNS server settings just select them and click the minus button, quite simple really.