I cannot open a file using firefox (neither "File->Open File..." nor "Ctrl+O"). I cannot attach a file if a website does not have a drag an drop feature! I have opened the browser with command "firefox -safe-mode" and all these are working there! I removed my extensions and add-ons, the theme is set on default, and the hardware acceleration is disabled! I purged firefox and installed it again. However, the problem is still there! Can anyone help me?!