Solved it on my machine, posting the fix in case it's the same for you.
Setup: Windows 11 25H2 (build 26200.8655), Ryzen 5 5600X, RTX 4060 Ti. Symptom was identical: MTA launcher opens, spins one CPU core for ~10-15s, then vanishes with no window and no error (exit code 0xC0000409, no crash dump).
Fix that worked: uninstall Virtual Desktop (the VR "Virtual Desktop Streamer"). After removing it, the current MTA build launches to the main menu and connects to servers normally.
Notes if you want to try it:
- It's specifically a full uninstall. Just disabling Virtual Desktop's display adapter in Device Manager did NOT help, you have to uninstall it so its service and driver are gone.
- Don't have Virtual Desktop? Then this exact cause isn't yours, but the pattern is the same: it's a regression on recent Windows (24H2/25H2) where some virtual-display/streaming driver trips the current client. The older official build r23409 launches regardless, if you can find that installer, it's a stopgap (but only joins servers whose minclientversion is at or below it).
- If you use Virtual Desktop for VR, the catch is you currently have to choose: Virtual Desktop installed for VR, or MTA working. Reinstalling VD re-breaks MTA until this is fixed upstream.
Tracked on GitHub here, please add your Windows build number and whether you have Virtual Desktop installed, more datapoints help the devs pin it: https://github.com/multitheftauto/mtasa-blue/issues/4953
