Watch the video:
Timestamps:
0:00 - Explanation
0:10 - The issue
0:40 - CS:GO Options fix
1:22 - Running CS:GO as Admin, and fixing
2:50 - Account switcher - Check Admin?
3:17 - Other fixes
With the new VAC update, a whole lot of people are locked out of playing competitive matches. This has an easy fix, and this video should work for most people without having to redownload the entire game. Hopefully, this explains it in an easy way.
TcNo Account Switcher: Go to post or View on YouTube
GitHub: https://github.com/TcNobo/TCNO-Acc-Switcher