Recently there have been a few users who got 0X11C7 error when launching the app, preventing them from playing certain games on Steam. Some users found it helpful to disable Smart App Control. This is done by going to Settings → Privacy & Security → Windows Security → App & browser control, and disable Smart App Control.
Fixes on lag and other issues - users have been compensated with gems.
OCR recognition for image QWERTY sheets.
Tuning setting e.g. 440Hz is the default
Steam Error Code 0X11C7, Fixes, OCR recognition for image QWERTY sheets, Tuning
Source: Steam Community (opens in a new tab)