This may be your problem, Firefox v52+ disables all plugins except for Flash [https://support.mozilla.org/en-US/kb/npapi-plugins Why do Java, Silverlight, Adobe Acrobat and other plugins no longer work?] {web link} [https://support.mozilla.org/en-US/kb/install-older-version-of-firefox?cache=no Install Older Version Of Firefox] {web link} Be sure to read everything here. If you still want to downgrade, look under; '''I still want to downgrade. ''' Click the '''Directory of other versions and languages''' link. Look for the directory of the version that you want. But, remember that '''old versions may have security issues. ''' You should also check out [https://www.mozilla.org/en-US/firefox/organizations/ Firefox; Extended Support Release] {web link} [https://www.mozilla.org/en-US/firefox/organizations/notes/ ESR Notes] [https://www.mozilla.org/en-US/firefox/organizations/system-requirements/ System Requirements] ---------------------- Also see; http://kb.mozillazine.org/JavaScript_is_not_Java

Firefox 52 and later releases only support the Shockwave Flash plugin and disable all other plugins. If you need to use other plugins then you can use the Firefox 52 ESR release. Otherwise you can stay with the current Firefox release version. *https://www.mozilla.org/en-US/firefox/organizations/all/ Why-do-Java-Silverlight-Adobe-Acrobat-and-other-plugins-no longer work. *https://support.mozilla.org/en-US/kb/npapi-plugins