I have Ubuntu 16.04 and when I launch some fullscreen aplications, they randomly (at a given moment) freeze my display. I can move the mouse pointer using the mousepad but neither I can't click nor press a key combination to exit the aplication. If I press Alt+F1 (I think), then I go completely into CLI. My question is, if I suspect that this is a bug from one or more of my repositories, how can I detect wich of them is buggy and how to file this bug (under which package)?
Thanks for your patiente, as I am new at this.