Plugin won't work

[Dayne11]

Here is my error:

2018-03-26 [14:40:07] �[Server thread/INFO]: Enabling DevTools v1.12.9�
2018-03-26 [14:40:07] �[Server thread/INFO]: Loading source plugin SnowballFight v0.2.0�
2018-03-26 [14:40:07] �[Server thread/INFO]: [DevTools] Registered folder plugin loader�
2018-03-26 [14:40:07] �[Server thread/INFO]: Preparing level "world"�
2018-03-26 [14:40:07] �[Server thread/INFO]: Enabling SnowballFight v0.2.0�
2018-03-26 [14:40:07] �[Server thread/CRITICAL]: Error: "Class 'pocketmine\scheduler\CallbackTask' not found" (EXCEPTION) in "plugins/SnowballFight-master/src/SnowballFight/Main" at line 1053�
2018-03-26 [14:40:07] �[Server thread/DEBUG]: #0 plugins/SnowballFight-master/src/SnowballFight/Main(124): SnowballFight\Main->gameStartWait()�
2018-03-26 [14:40:07] �[Server thread/DEBUG]: #1 src/pocketmine/plugin/PluginBase(90): SnowballFight\Main->onEnable()�
2018-03-26 [14:40:07] �[Server thread/DEBUG]: #2 plugins/PocketMine-DevTools (3).phar/src/FolderPluginLoader/FolderPluginLoader(127): pocketmine\plugin\PluginBase->setEnabled(boolean 1)�
2018-03-26 [14:40:07] �[Server thread/DEBUG]: #3 src/pocketmine/plugin/PluginManager(567): FolderPluginLoader\FolderPluginLoader->enablePlugin(SnowballFight\Main object)�
2018-03-26 [14:40:07] �[Server thread/DEBUG]: #4 src/pocketmine/Server(1965): pocketmine\plugin\PluginManager->enablePlugin(SnowballFight\Main object)�
2018-03-26 [14:40:07] �[Server thread/DEBUG]: #5 src/pocketmine/Server(1951): pocketmine\Server->enablePlugin(SnowballFight\Main object)�
2018-03-26 [14:40:07] �[Server thread/DEBUG]: #6 src/pocketmine/Server(1742): pocketmine\Server->enablePlugins(integer 1)�
2018-03-26 [14:40:07] �[Server thread/DEBUG]: #7 src/pocketmine/PocketMine(385): pocketmine\Server->__construct(BaseClassLoader object, pocketmine\utils\MainLogger object, string /home/dynamicmcpe/, string /home/dynamicmcpe/plugins/)�
2018-03-26 [14:40:07] �[Server thread/INFO]: Disabling SnowballFight v0.2.0�

[Dayne11]

I am assuming it is in line 1053...
2018-03-26 [14:40:07] �[Server thread/CRITICAL]: Error: "Class 'pocketmine\scheduler\CallbackTask' not found" (EXCEPTION) in "plugins/SnowballFight-master/src/SnowballFight/Main" at line 1053�

[chell-uoxou]

Thank you for trying to use it. I'm gonna fix it.
You are using API-3.0.1 or higher, right?

[Dayne11]

Correct, the newest verison.

[PawarenessC]

There is no CallbackTask in the current PMMP.