I have a persistent USB installation of Ubuntu 14.04. Firefox would not play MPeg4, AAC or QuickTime -- so I tried to install the "restricted-extras". The install progress bar went 3/4 to 4/5th of the way and then after a long delay the Window went "dim" and eventually the OS indicated "No Response" from the process.
I tried several times all with the same result - even rebuilding the Ubuntu installation.
Even with the partial installation Firefox would now play videos - but when I went to install Wine and Mono they both would not even start due to missing dependencies. I am suspect of the "fonts" (supposedly to be installed by the package) that they may not be there because the process locked-up and quit, that perhaps Wine and Mono want them but I just don't know and although a professional I am very new to Linux.