There might be a few variants of this error:
This indicates that the graphics driver is misbehaving, and refuses to even let us know what graphics devices are available in your system.
In most cases, this is due to Windows Update partially installing something, and leaving Windows in a limbo state. If you let Windows Update finish installation (you'll probably need to reboot), this typically goes away.
It could also be that some automatic driver update process has messed something up in the system, and updating or reinstalling your graphics drivers might help.
You might also see this error if you happen to have an AMD CPU and an NVIDIA GPU. Sometimes Windows comes with extremely outdated drivers that mess things up. Installing AMD drivers for the integrated graphics chip of your AMD CPU should help in this case: https://www.amd.com/en/support/download/drivers.html
If you see some other variant of this error, please let us know in the Steam forums. Knowing which graphics card, driver and operating system you use would come in handy then.