I cannot install extensions in Firefox 4. For an extension marked as compatible with Firefox 4.0b2pre, when clicking on the install button, Firefox displays a popup balloon saying that it could not be installed because Minefield cannot modify the needed file. I have correct rwx access rights on all the application and profile's files. Also, the Error console contains the following entry: '''_ Warning: WARN addons.xpi: Failed to start download: [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIProperties.get]" nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame :: resource://gre/modules/FileUtils.jsm :: FileUtils_getDir :: line 62" data: no] '''_ When I download manually the extension I am willing to install, and open it with Firefox, I am presented the usual popup window asking for confirmation. When validating, the window disappears and the extension is showing in the addons manager. But the addon behave likes it was broken (no action, disabled icon in the toolbar, etc); hinting that something is wrong in the installation. I suspect that Firefox is not able to access correctly my profile; I did put it on another volume and created a softlink pointing to it. My system is Mac OS X Snow Leopard. == This happened == Every time Firefox opened == started with Firefox v3.6 and continues with Firefox v4 == == User Agent == Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; en-US; rv:2.0b2pre) Gecko/20100709 Minefield/4.0b2pre