Have you got the NoScript add-on installed? That deals with turning on Javascript on a per site basis (it disables Javascript but you can enable it for chosen sites). If you have, then you'll need to change it so that either NoScript allows adobe.com or you can temporarily allow the site (right-click on the NoScript icon to change). Anyway, the NoScript website will have further help if this is the problem. If you don't have this add-on installed, then we'll need to check whether a setting in about:config has changed. about:config is Firefox's advanced configuration tool (so be careful). Open a fresh tab, enter "about:config" (no quotes) into the address bar, click the warning button (there be dragons), then enter "javascript.enabled" (no quotes) into the search bar of about:config, which should find the relevant setting. If Javascript is running, then its value should be set to true. If it's set to false, then you'll need to double-click the entry (or right-click and select toggle) to set it to true to enable Javascript.