Anuken/Mindustry · warning · ValidateException

Player cannot respawn.

Error message

Player cannot respawn.

What it means

Thrown server-side as ValidateException in unitClear when netServer.admins.allowAction(respawn) returns false. Guards the respawn/leave-unit action behind the admin permission layer; a denied respawn aborts the packet.

Source

Thrown at core/src/mindustry/input/InputHandler.java:826

            Time.run(Fx.unitSpirit.lifetime, () -> Fx.unitControl.at(unit.x, unit.y, 0f, unit));
            if(!player.dead()){
                Fx.unitSpirit.at(player.x, player.y, 0f, unit);
            }
        }else if(net.server()){
            //reject forwarding the packet if the unit was dead, AI or team
            throw new ValidateException(player, "Player attempted to control invalid unit.");
        }

        Events.fire(new UnitControlEvent(player, unit));
    }

    @Remote(targets = Loc.both, called = Loc.server, forward = true)
    public static void unitClear(Player player){
        if(player == null) return;

        //make sure player is allowed to control the building
        if(net.server() && !netServer.admins.allowAction(player, ActionType.respawn, action -> {})){
            throw new ValidateException(player, "Player cannot respawn.");
        }

        if(!player.dead() && !player.unit().spawnedByCore){
            var docked = player.unit().dockedType;

            //get best core unit type as approximation
            if(docked == null){
                var closest = player.bestCore();
                if(closest != null){
                    docked = ((CoreBlock)closest.block).unitType;
                }
            }

            //respawn if necessary
            if(docked != null && docked.coreUnitDock){
                //TODO animation, etc
                Fx.spawn.at(player);

View on GitHub (pinned to f695ad7e60)

Solutions

1. Server: handle ValidateException as an expected denial rather than propagating.
2. Review netServer.admins rules / permission plugin config if legitimate respawns are blocked.
3. Clients can pre-check permissions if the server exposes them, otherwise expect possible denial.

Example fix

// before
Call.unitClear(player);

// after (server-side handler)
try{
    // remote invocation path
}catch(ValidateException e){
    Log.debug("@ denied respawn: @", e.player, e.getMessage());
}

// no generic client pre-check for permissions; clients may pre-check rules if exposed
if(/* server-exposed permission check */ false){ return; }

try{ Call.unitClear(player); }catch(mindustry.net.ValidateException e){ Log.debug("rejected respawn from @", e.player); }

When it happens

Trigger: Client sends unitClear (request to leave current unit / respawn at core) and the admin layer denies the respawn action. Server-side throw in the @Remote handler.

Common situations: Permission plugin restricts respawning; server config disables free respawn; a client spams respawn while a cooldown/permission blocks it.

Related errors

• Player cannot configure a tile.
• Player cannot control a building.
• Player cannot control a unit.
• Player attempted to control invalid unit.
• Map has no cores!

AI-assisted analysis of Anuken/Mindustry@f695ad7e60 (2026-08-14). Data as JSON: /api/errors/c4a186e3e8b03e79. Report an issue: GitHub.