Force Firefox to install add-on

I wanted to install a new add-on in Firefox – Firesheep, but when I tried to do so (from an xpi file), it told me that it can be installed because it's incompatible for 4.0.1.

However, compatibility check is disabled. Is there any way to force the add-on to install?

genesis

Posted 2011-06-24T21:23:45.447

Reputation: 288

– slhck – 2011-06-24T21:31:52.697

as I said, compatibility check is disabled. (same way) – genesis – 2011-06-24T21:35:34.707

I know, that's why I said "related" and not "duplicate" :) – slhck – 2011-06-24T21:36:43.643

Have you discovered an answer? I am having the same issue, I am using the add-on compatibility reporter yet I cannot get an add-on to install... – L84 – 2011-09-30T20:47:30.773

Answers

You can use Add-on Compatibility Reporter. With this extension Firefox will install all extensions whether they are compatible or not. Additionally from the Addons Manager you can report (if you want) if a given extension is incompatible with the current version of Firefox or report bugs.

Realcool

Posted 2011-06-24T21:23:45.447

Reputation: 127

Thanks. However, it didn't work out. It just showed the same thing as before (maybe because that add-on does not check installs from files?), however I can't find Firesheep anywhere in official add-on database – genesis – 2011-06-25T00:42:05.383

With this you just can force Firefox to install any extension, but not to force the compatibility. – Realcool – 2011-07-18T16:46:46.643

1This doesn't work since firefox 10. – naught101 – 2012-05-07T00:13:32.450

As far as I'm concerned you can "hack" an xpi file to change the maximum version required.

Rename the xpi to zip and extract it with your favorite unarchiving software
Find the install.rdf file and open it in a text editor
Change the following line (if you're talking about this Firesheep):
```
<em:maxVersion>3.6.*</em:maxVersion>
```
to that one:
```
<em:maxVersion>4.0.1</em:maxVersion>
```
Save the file and zip the whole folder again.
Rename the zip into xpi and try to install the add-on again.

Note that this does not necessarily make the add-on work, but it should at least install.

slhck

Posted 2011-06-24T21:23:45.447

Reputation: 182 472

I tried to change that too, I changed that to 5.0.* – genesis – 2011-06-24T21:37:51.447

1Hm, should have mentioned in your question then! :) I don't know, this has worked for me once. – slhck – 2011-06-24T21:39:28.180

download this version of mozila, it should work perfectly : https://ftp.mozilla.org/pub/firefox/releases/3.6.28/win32/en-GB/

Slic0007

Posted 2011-06-24T21:23:45.447

Reputation: 1

While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. – Donald Duck – 2017-08-25T10:02:16.160

If all else fails, here are some links to download previous versions of Firefox:
https://ftp.mozilla.org/pub/mozilla.org/firefox/releases/

You'll probably want version 3.6:
https://ftp.mozilla.org/pub/mozilla.org/firefox/releases/3.6/win32/en-US/

w3bshark

Posted 2011-06-24T21:23:45.447

Reputation: 101

This is a very old version of Firefox, and the question itself is probably no longer relevant. – bwDraco – 2012-10-11T15:33:59.640