HI, you have not mentioned what your native language is, nor what version of Firefox language you are using ex ; English or what have you installed, *https://www.mozilla.org/firefox/all/ what language dictionary you maybe using for your spell checking as need one for spell checking. *https://addons.mozilla.org/en-US/firefox/language-tools/ Nor explained in detail what this little pop-up looks like or info or ....... Until we have some more detail nothing as of yet to help with. So please supply more info. Thank You.