FIXED

You need to change issuer to data when using an event. Then to get the player go to $data["player"]. Here is the fixed code:

PHP:

<?php
/*
__PocketMine Plugin__
name=JoinMessage
version=1.0.0-BETA
author=JassperBeastHD
class=message
apiversion=10
*/
class message implements Plugin
{
private $api;
public function __construct(ServerAPI $api, $server = false)
{
$this->api = $api;
}
public function init()
{
$this->api->addHandler("player.join", array($this, "handler"), 5);
$this->api->addHandler("player.respawn", array($this, "handler"), 5);
}
public function __destruct(){
}
public function handler($data, $event){
$player = $data["player"];
switch($event){
case "player.join":
$player->sendChat("====[SBP Server]====\nWelcome @player to SBP Server\n-Owner=XxSilentBeastxX_\n-Youtube=XxSilentBeastGamerxX\n-Co-Owner=JassperBeastHD\n-Youtube=JassperBeastHD\n====[SBP Server]====\n");
break;
case "player.respawn":
$player->sendChat("====[Death Message]====\n-You died\n-To bad you lose your stuff\n-Make sure to get your stuff back\n====[Death Message]====\n");
break;
}
}
}

I'm pretty tired though and could be wrong

Yes you could do that, but it would be $data["player"]

Could you tell me what it says is illegal?

Did you just use my code or did you change it?

Weird, I didn't know what's wrong with it, wait for someone more experienced

Just change $player = $data["player"]; to $player = $data;

Make sure you have $player->sendChat and not $issuer->sendChat

I don't have much server access and the cloud server I manage is being stupid