Missing /lib/libc.so.6
A quick solution.
Open a terminal (Ctrl+Alt+T) and run the following commands:
For 64-bit Ubuntu:
sudo ln -s /lib64/x86_64-linux-gnu/libc.so.6 /lib64/libc.so.6
For 32-bit Ubuntu:
sudo ln -s /lib/i386-linux-gnu/libc.so.6 /lib/libc.so.6
On my 64-bit Ubuntu it needed to be:
sudo ln -s /lib/x86_64-linux-gnu/libc.so.6 /lib/libc.so.6
(i.e. the 64 bit library is below /lib, not /lib64)