FAQ

/alert says "unknown command"

The mod isn't installed (or isn't loaded) on that side. Alert Mod has to be on both the client and the server — it's not a client-only or server-only mod.

I ran /alert but nothing happens

You need permission level 2 (operator) to use it. If you're not an operator, the server will tell you so in chat instead of opening the screen.

The screen opened but I don't see the alert after sending

Check that:

• You didn't deselect yourself in the player list before deselecting everyone else (deselecting everyone sends to everyone, but deselecting everyone except yourself sends to everyone but you).
• The message box wasn't empty — an empty message is silently ignored.

No sound plays

Make sure the Sound toggle in the screen was on when you sent the alert, and that your Minecraft "Master" volume isn't muted (the siren plays in the Master category).

Can I translate the mod into another language?

Yes — the mod ships English and Portuguese out of the box (assets/alertmod/lang/en_us.json, pt_br.json). Adding another language is just adding another xx_xx.json file with the same keys. See For Developers.