Firefox 3.5 override
From Galaxytool wiki
If you need to install Galaxyplugin 2.1.x into Firefox 3.5 use this addon ( https://addons.mozilla.org/de/firefox/addon/6543 ) to override any compatibility issues Firefox might bring up.
1
Download and install Nightly Tester Tools
2
Restart Firefox
3a
existing installation of galaxypluging: go to Extras--> Addons and click "override compatibility in the bottom right
3b
new installation of 2.1.9 install as usual and click "force install" (screenshot below)
4
Restart Firefox
5
Enjoy Galaxyplugin 2.1.x with Firefox 3.5
you may delete Nightly Tester Tools as soon as you have a compatible version (either 2.1.10 or 2.2.x) at your disposal.