Fatal error:Class 'Netzmacht\ColumnSet\Hooks' not.

A »Fatal error« appears  because the Hooks:: isVisibleElement()
method is is defined for Array $GLOBALS['TL_HOOKS']['isVisibleElement'][] in Line:15 > config.php.
The proclamation for the ClassLoader is missed in autoload.php.
With the added line, the Fatal error is past.

I hope it will help
Martin