"A debugger has been found running in your system."

Some anti-virus vendors run programs in a virtual machine. If you aren`t using an anti-virus, then make sure Hyper-V is disabled.

"File corrupted! This program has been manipulated and maybe it's infected by a Virus or cracked. This file won't work anymore."

Your antivirus program has quarantined the launcher and is preventing from running. Try to add the download folder to your antivirus exceptions.

Mod menu not displaying or flickering

Make sure the Steam overlay is enabled. Check it is enabled in both of these places:

• Steam > Settings/Preferences > In-game tab. Check the box next to Enable the Steam Overlay while in-game.
• Right-click "Counter-Strike 2" in your Library > Select Properties > Under the General tab, check the box next to Enable the Steam Overlay while in-game.