Newly installed Firefox to replace Safari on MacPro. Installed downloaded file which has extension .dmg and Firefox does not appear as an .app. Set it as the default browser and checked permissions. Whenever click a link I receive the error message "The application cannot be opened" 10826, see image below. In order to open a link I have to copy the link and manually paste it in the Firefox search window to get to the link. Driving me nuts, please help. Alex