Well, I don't know for sure because I haven't experienced this, but if it says "Permission denied" for the file/folder /dev/tty0, then simply login as root instead, open a command console, and type
sudo chmod 777 /dev/tty0 #(or however much permission you want to give it)
That will make it entirely executable, readable, and writable by everyone (a bit dangerous, so give it your value that you desire - that just makes it failsafe permission wise in the sense that there is no way you can't run it because of permissions).
-Stephen



