Tracking protection is just this: By default, your web browsers will load every resource used in a web page. On popular sites, that usually includes numerous external images, advertisements, and scripts with an emphasis on analytics and tracking. If you ever watched the numerous different server names flashing by in the lower left corner while a page is loading, you've probably noticed how many sites your browsers are instructed to contact when you load a page. Over the years, there have been several add-ons designed to block some of these external resources, and starting in Firefox 42, Mozilla has partnered with one of those companies to provide built-in blocking in private windows. On the plus side this speeds up page loading and better protects your privacy. On the minus side, useful content may occasionally be blocked. Our support article "[[Tracking Protection in Private Browsing]]" explains how you can allow the blocked content in those cases. ---- Regarding this issue: <blockquote> i have been having alot of problems with script errors and "not responding" lockups. </blockquote> Have you noticed any pattern as to which sites cause this problem? In past forum threads, some common culprits that affect multiple sites are: * The Skype Click-to-Call extension * The Flash plugin "protected mode" feature '''''To manage extensions''''' Open the Add-ons page using either: * Ctrl+Shift+a * "3-bar" menu button (or Tools menu) > Add-ons In the left column, click Extensions. Then review your list on the right side and disable anything you don't plan to use for the next 48 hours. Especially if you don't recognize it. Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step. '''''Taming Flash''''' Since Flash can cause this problem and it is used pervasively through the web, I suggest the following to minimize potential issues with Flash during your troubleshooting: (1) A common cause of unresponsive script errors on Windows Vista and higher is the protected mode feature of the Flash player plugin. That feature has security benefits, but seems to have serious compatibility issues on some systems. You can disable it using the Add-ons page. Either: * Ctrl+Shift+a * "3-bar" menu button (or Tools menu) > Add-ons In the left column, click Plugins. On the right side, find "Shockwave Flash" and click the More link. Then ''uncheck'' the box for "Enable Adobe Flash protected mode" and try that for a day to see whether it helps. (2) If problems persist, try setting Flash to Click-to-Play ("Ask to Activate"). This will delay Flash from starting on a page until you approve it and help distinguish between problems caused on initial page load, styling, and script activation vs. loading/running Flash. To set "Ask to Activate", open the Add-ons page using either: * Ctrl+Shift+a * "3-bar" menu button (or Tools menu) > Add-ons In the left column, click Plugins. Look for "Shockwave Flash" and change "Always Activate" to "Ask to Activate". With this setting, when you visit a site that wants to use Flash, you should see a notification icon in the address bar and usually (but not always) one of the following: a link in a dark gray rectangle in the page or an infobar sliding down between the toolbar area and the page. The plugin notification icon in the address bar typically looks like a small, dark gray Lego block. (If it's red, Flash needs updating.) If you see a good reason to use Flash, and the site looks trustworthy, you can go ahead and click the notification icon in the address bar to allow Flash. You can trust the site for the time being or permanently. But some pages use Flash only for tracking or playing ads, so if you don't see an immediate need for Flash, feel free to ignore the notification! It will just sit there in case you want to use it later.