MultiRoblox not working
If MultiRoblox is not working, or the second Roblox window is not opening after an update, start here before reinstalling from a random site.
Second window never appears
Fully close every Roblox process in Task Manager, enable multi-instance, start the first client, then the second. Run the helper before you click Play in the browser.
Only one account stays logged in
Each window has its own login. Do not use Stay logged in flows that collapse to a single browser cookie if you intended two identities.
Broke after a Roblox update
Desktop Player updates can invalidate unofficial helpers. Use Microsoft Store plus Player as a two-window fallback, then update MultiRoblox from this site — not from a random fixed 2026 GitHub fork you have never heard of.
Stutter or black screens
Lower graphics, disable shadows, cap FPS, close the extra browser. See low-end PC and requirements.