Multi Instance

How Multi-Instance Works

Roblox prevents multiple instances using two mechanisms:

1. ROBLOX_singletonMutex — a Windows named mutex

2. Process detection — Fishstrap checks for running processes

Alt Central handles both automatically:

• Bootstrapper auto-config — detects Fishstrap/Bloxstrap/Voidstrap and enables multi-instance

• Native mutex holder — mutex_holder.exe holds the mutex for vanilla Roblox

Fishstrap / Bloxstrap / Voidstrap

Alt Central auto-enables multi-instance on startup. If it's still not working, configure manually:

1

Open Bootstrapper Settings

Find settings at:

• Fishstrap: %LOCALAPPDATA%\Fishstrap\Settings.json

• Bloxstrap: %LOCALAPPDATA%\Bloxstrap\Settings.json

2

Enable Multi-Instance

Turn ON: "Allow multi-instance launching" Turn OFF: "Confirm launches"

3

Restart

Close and restart the bootstrapper, then try Alt Central again.

Error 773: Place is Restricted

This is the most common multi-instance bug with ERLC.

ERLC teleports players from a lobby to the actual server. When multiple instances share RobloxCookies.dat, the teleport auth gets mixed up.

Alt Central's fix: You cant know this silly!

If you still get 773:

1. Click Leave All to close everything

2. Wait 10 seconds

3. Relaunch — the cookie file should be clean

Under-13 accounts cannot join ERLC. If only some alts get 773, those accounts likely have under-13 birthdays. Use 13+ birthday accounts.

Instances Closing Each Other

This happens when the bootstrapper has multi-instance disabled. Each new launch kills the previous instance.

Fix: Enable multi-instance in bootstrapper settings (see steps above).