Problem starting Steam on ubuntu 15.04 64-bit

Solution 1:

cd $HOME/.steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu
mv libstdc++.so.6 libstdc++.so.6.bak
cd $HOME/.steam/ubuntu12_32/steam-runtime/amd64/usr/lib/x86_64-linux-gnu
mv libstdc++.so.6 libstdc++.so.6.bak

Type these into the terminal; it worked for me. Copied from this thread, posted by sejvenables, who copied it from someplace else.

Solution 2:

I had the same problem on Ubuntu 15.10, with an nvidia board. WPOH's solution made Steam work, but caused noticeable performance and mouse lag issues on some games.

Using the proprietary nvidia drivers fixed the problem without impacting the performance.

To revert those changes:

mv $HOME/.steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libstdc++.so.6{.bak,}
mv $HOME/.steam/ubuntu12_32/steam-runtime/amd64/usr/lib/x86_64-linux-gnu/libstdc++.so.6{.bak,}

And to install the updated proprietary nvidia drivers: open "Software & Updates", go to "Additional Drivers", select the latest binary nvidia driver (352.41 as of now) and then reboot the system. That did the trick for me :)