Just checked and the same error message pops up. Also Source games (CS:GO and others) fails to load with a “glGetError”
On a side note about Steam, I was going to uninstall it and reinstall but when you uninstall it from the Boutique it uninstalls the launcher but not Steam it’s self. Leaving all of the games and Steam in place and still working with just the launcher uninstalled.
Update, The odd error message when you start Steam is still present. However the error that was preventing Source games from running appears to be resolved.