Let Older Add-Ons Work With Firefox 3.0

mask.of.sanity informs us of a hack that allows old add-ons to work with Firefox 3.0. Short form: in about:config, create a new boolean and set extensions.checkCompatibility to false. "The fix, which requires a little boolean creativity, great for anyone not afraid of taking risks. The idea is to stop Firefox checking its version history, allowing defunct extensions to work... [Those who do] get the fix working will have to remove the code from the prefs.js file once the stable Firefox comes out, but will enjoy their [favorite extensions] in the meantime."

Do not do this

[amake]

Not only is this not news, but it's a bad idea. Straight from the horse's mouth: [mozillazine.org]

You can not make your extensions compatible by changing a Firefox preference.

So don't do it unless you're fully prepared to deal with major breakage!

Re:Do not do this

[DuncanE]

While it may cause breakage its a great way for users of the beta and RC version of Firefox 3 to get some fairly major extensions work.

I need IEtab to get certain work pages to work and I really love stumbleupon... So when Firefox 3 upgraded automatically to RC1 and these broke it was quite annoying so i disabled the check.

An example of an extension this wont fix is Google Browser Sync. You will need to disable this in Firefox 3 otherwise you WILL see some major breakage if you disable the check.

Takes a long time to filter

[IBBoard]

Obviously tips like this take a long time to filter through to Slashdot, for some reason. I saw that tip when first using Firefox 3 betas, and according to the Mozillazine knowledgebase [mozillazine.org] it has been there since Firefox 2! It also covers an extra bit that the summary doesn't that might still stop extensions working in Firefox 3.

And after all that, I originally used the Nightly Tester Tools to check the compatibility of some extensions. Some of the simpler ones worked, but AdBlock Plus couldn't just have the FF2 version enabled (it wouldn't auto-fill the filter address, but they have an update) and neither could the Web Dev toolbar (the edit CSS tab wouldn't close, amongst other things). Both of them have now been updated for the RC.

I think this one is definitely tagged right - "!news". Now all it needs is "badidea".

Nightly Tester Tools

[DemonThing]

This addon [mozilla.org] lets you selectively override addons' compatibility, among other things.

This extension adds a few extras useful to those that regularly test nightly builds of Firefox, Thunderbird, Sunbird and Toolkit Seamonkey (Suiterunner).

The following is a brief list of the extension's features, for the full set of features please visit the extension home page.

• Extension compatibility fixing
• Titlebar customisation
• Build ID retrieval
• Screenshots
• Breakpad information
• Restoring tabs from previous session
• Leak log analysis

Re:No Foxmarks...

[Cyvros]

There's a beta version of Foxmarks [foxmarks.com] for Firefox 3 that's now been opened.

Test the extentions one at a time

[fairyprincess]

Every extention has an install.rdf file which contains the version numbers it works with, if you go to your profie dir and then extentions you can move the extention folders out, edit the rdf files in notepad then restart firefox - it will have no extentions, close it, then move all the extention folders back one at a time restarting firefox everytime, that way you are only adding back extentions that you know work, but just haven't been updated by their developers to install. This can also be done by renaming the .xpi files to .zip then opening editing then returning to .xpi and installing. If you are comfortable doing this i view this as safer than just allowing all addons as if something was crashing firefox you would have no idea, where as if it did you would know and you would live without one extention rather than one.

This is really, really stupid

[Idaho]

Sure you can disable the mechanism that checks whether plugins are compatible.

However, as is to be expected with major version changes, lots of API's will likely have changed, so if the plugins happen not to crash outright, they might fail in subtle ways that you don't discover until it's much too late.

This is pretty much exactly why the mechanism is there in the first place.

So if you do this, don't complain about "bugs" regarding crashes, memory leaks and pretty much any other problems you may experience with Firefox. There likely will be a lot, if you go down this road.

Re:A bit less strict disabling rules, please

[rubah]

Both. Things like forecast fox don't depend so much on the browser so long as they can sit happily in the statusbar (at least how I use it it's happy), but things like firebug get honest-to-gosh broken. As in you can open it and use it to edit css to show in a page, but it will not call the stylesheets or outline an element you hover over. So it's still kinda useful but heavily limited.

for a given of 'small bugfix' anyways.

Re:Do not do this

[Keeper Of Keys]

I did this; basically don't want to live without Google Toolbar. But the current version makes FF3 unstartable. I had to manually rip it out my extensions folder.

In any case, there' no need to hacking around in about:config; just use the Nightly Tester Toolds [oxymoronical.com].

Re:A bit less strict disabling rules, please

[Keeper Of Keys]

There is a beta (1.1) on the Firebug page [getfirebug.com] which works just fine in FF3.

Re:Do not do this

[GigaplexNZ]

Odd, IE Tab is working fine here on FF 3 RC 1 without any modifications. That said, I find a safer way to get your favourite extensions working is to edit the version number in install.rdf which is inside the .xpi file (xpi is just a renamed zip file). That way when the extension updates normally, the hack doesn't stick around ready to break something later.

Re:A bit less strict disabling rules, please

[Anonymous Coward]

Some extensions devs will compare their extension with the current version of Firefox, say 2.0.0.14, make sure it works, and publish an extension with the max-version set to 2.0.0.14. This is what they are "supposed to" do.

Wrong. Firefox's versioning policy is that changes in the fourth component don't break compatibility (or at least shouldn't, but if it happens it's a bug). That's the reason they have four components in the first place: the third is there in case they need to do a security fix that breaks extensions, but doesn't have any/enough user-visible improvements to justify bumping the first two.

Some devs "break the rules", and if the current version is 2.0.0.14, they will set the max-version of their extension to 2.0.0.99, or something like that.

IIRC it accepts wildcards, but otherwise that's entirely the right thing to do.

Google bar kills my FF3

[MadMidnightBomber]

You have been warned :)

Recovery is to delete the plugin, something like this:
egrep -ri google .mozilla | grep toolbar
.. ( see where it lives ) ..
rm -rf .mozilla/firefox/zy8uo2wh.default/extensions/\{3112ca9c-de6d-4884-a869-9855de68056c\}

Re:A bit less strict disabling rules, please

[maxume]

There is a goal inside of Mozilla not to break extension compatibility for minor releases, and the documentation on their website suggests using maxVersion of the form 2.0.0.* for Firefox 2:

http://developer.mozilla.org/en/docs/Updating_extensions_for_Firefox_2#Step_1:_Update_the_install_manifest [mozilla.org]

For Firefox 3, they suggest moving to the form 3.0.*:

http://developer.mozilla.org/en/docs/Updating_extensions_for_Firefox_3#Step_1:_Update_the_install_manifest [mozilla.org]

So no, devs aren't breaking any rules when they mark their extension as being forward compatible.

Re:Do not do this

[nmg196]

Why? IETab doesn't use Gecko, it uses IE. That's the entire point of it.

Re:Google bar kills my FF3

[mstrom]

Recovery is to delete the plugin, something like this:

...

Ouch,manual removal of add-ons :(

Simpler way is to start Firefox in safe mode which has an option to disable all addons on startup, after which it can be uninstalled from within firefox safely.

firefox -safe-mode if my memory serves

Disabled install button

[lofoforabr]

Well, I've been using this pref since the early days of Minefield. I find that most extensions I use work fine under Minefield. Here is a list of them:

• Adblock Plus
• del.icio.us
• Fasterfox
• Flashblock
• Greasemonkey
• Live PageRank
• NoScript
• Web Developer Toolbar

One thing to note, though.. I think recently the mozilla addons site has been changed, and the button to install is now disabled if you use a not-officially-compatible browser version.

To overcome this, I first install NoScript (it's compatible with Minefield), and then blacklist the mozilla addons site, so it will not run the javascript that disables the button (yes, it's javascript). Then I can install whatever I want.

Of course, I had a few problems with some extensions. Turned out they really were incompatible, but from my personal experience, most of them work just fine under Minefield.

Re:Do not do this

[The MAZZTer]

You DO realize safe-mode exists so you can uninstall and disable extensions without having them running, so they can't crash Firefox.

Firefox Portable

[EnOne]

I would recommend Firefox Portable if you want to see if FF3rc1 is right for you. No registry changes and it allows you to add your extensions without issue. I have 10 add-ons that I use with Firefox and last time I tried to do a blind upgrade with forced add on use Firefox would not even start.

Re:Do not do this

[Myen]

It's a NPAPI plugin with XPCOM interfaces to expose it to the UI. That is, it's tied to both sets of APIs. Notice how the back button actually seems to work?

Re:Do not do this

[BZ]

It hooks into the binary parts of Gecko to actually show the content Trident renders.

Re:rickst29

[rickst29]

To be absolutely safe, back up your profile directory from OUTSIDE Firefox and 'turn on' only a few at a time. If it breaks so badly that Firefox won't even start, just restore the proofile directory from one of your "backup" copies. BTW, there's some out-of-date comments here, NTT does not force you to "make ALL compatible" at the same time anymore.