MSFN is made available via donations, subscriptions and advertising revenue. The use of ad-blocking software hurts the site. Please disable ad-blocking software or set an exception for MSFN. Alternatively, register and become a site sponsor/subscriber and ads will be disabled automatically.
The following helped me: Hit the Windows Start button In the search box, type "cmd" but DO NOT PRESS "ENTER". Press and hold "CTRL-Shift" on your keyboard while pressing "ENTER". You'll be prompted with a permission dialog box. In the box, click "YES". You should have a black screen with a blinking cursor. In that black screen, type "sfc /scannow" and hit "ENTER". SFC will begin scanning for quartz.dll.mui issues and any other system file problems. Follow any on-screen commands to complete the process.