"Software installation is currently disabled ..." This message appears while trying to install Flashblock from the web. I can't find anything in the Tools-Options pages to "enable". Am I 'geezing' or what am I missing?
For reasons too tedious to reiterate the Firefox developers decided to remove that setting from Tools->Options in FF 1.5. This naturally confused a lot of people used to FF 1.0.x.
The long way around:
* In the URL (address) bar type the following without the quotes: "about:config"
* In the filter box type "xpinstall".
* In the filtered list you should see an entry called: "xpinstall.enabled". Double-clicking on this option will toggle it between true and false. Make sure that it is set to "true".
* Also toggle "xpinstall.whitelist.required" to false since you also can't access the whitelist from the Options pages in FF 1.5.
* Install Flashblock from the web.
* To be on the safe side toggle all these settings back to the original values after installing Flashblock.