What did I do wrong

I'm wondering what I did wrong but I'm stuck lol (BTW it's my first plugin)

Here's my crash dump:

PocketMine-MP Crash Dump Mon Aug 24 07:06:51 UTC 2015

Error: Class _jigibbs123\SimpleRank\Main not found
File: /src/spl/BaseClassLoader
Line: 131
Type: notice

THIS CRASH WAS CAUSED BY A PLUGIN

Code:
[122] *
[123] * @return bool
[124] */
[125] public function loadClass($name){
[126] $path = $this->findClass($name);
[127] if($path !== \null){
[128] include($path);
[129] if(!\class_exists($name, \false) and !\interface_exists($name, \false) and !\trait_exists($name, \false)){
[130] if($this->getParent() === \null){
[131] throw new ClassNotFoundException("Class $name not found");
[132] }
[133] return \false;
[134] }
[135]
[136] if(\method_exists($name, "onClassLoaded") and (new ReflectionClass($name))->getMethod("onClassLoaded")->isStatic()){
[137] $name:nClassLoaded();
[138] }
[139]
[140] $this->classes[] = $name;
[141]

Most likely the fault is in plugin.yml

K thanks I'll have a look at it