{nav icon=home, name=Main Page > icon=wrench, name=Troubleshooting > Firefox compat mode} Enable Firefox compat mode to install add-ons from Mozilla add-on website --- Open `PureBrowser` and type **//about:config//** into location bar and hit Enter, a warning will popup: {F32076, size=full, alt=ff1} Click !!I'l be careful, I promise!!! button, and type **//useragent.compat//** into the search bar, then double-click the preference to change its value to **true**: {F32078, size=full, alt=ff2} NOTE: From recently, you cannot install Firefox add-ons without changing your useragent string. To do this, open **//about:config//**, right-click, select //New// -> //String// and enter `general.useragent.override` and enter `Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0` as a string value, click okay and reload the page.