After deleting I get the error again and some more. This file was generated in the folder ztemp/doctrinemodels

Zikula_Doctrine2_Entity_CategoryProxy.php

<?php

namespace DoctrineProxy;

/**
 * THIS CLASS WAS GENERATED BY THE DOCTRINE ORM. DO NOT EDIT THIS FILE.
 */
class Zikula_Doctrine2_Entity_CategoryProxy extends \Zikula_Doctrine2_Entity_Category implements \Doctrine\ORM\Proxy\Proxy
{
    private $_entityPersister;
    private $_identifier;
    public $__isInitialized__ = false;
    public function __construct($entityPersister, $identifier)
    {
        $this->_entityPersister = $entityPersister;
        $this->_identifier = $identifier;
    }
    /** @private */
    public function __load()
    {
        if (!$this->__isInitialized__ && $this->_entityPersister) {
            $this->__isInitialized__ = true;

            if (method_exists($this, "__wakeup")) {
                // call this after __isInitialized__to avoid infinite recursion
                // but before loading to emulate what ClassMetadata::newInstance()
                // provides.
                $this->__wakeup();
            }

            if ($this->_entityPersister->load($this->_identifier, $this) === null) {
                throw new \Doctrine\ORM\EntityNotFoundException();
            }
            unset($this->_entityPersister, $this->_identifier);
        }
    }
    
    
    public function getId()
    {
        $this->__load();
        return parent::getId();
    }

    public function setId($id)
    {
        $this->__load();
        return parent::setId($id);
    }

    public function getParent()
    {
        $this->__load();
        return parent::getParent();
    }

    public function setParent(\Zikula_Doctrine2_Entity_Category $parent)
    {
        $this->__load();
        return parent::setParent($parent);
    }

    public function getChildren()
    {
        $this->__load();
        return parent::getChildren();
    }

    public function setChildren($children)
    {
        $this->__load();
        return parent::setChildren($children);
    }

    public function getLocked()
    {
        $this->__load();
        return parent::getLocked();
    }

    public function setLocked($locked)
    {
        $this->__load();
        return parent::setLocked($locked);
    }

    public function getLeaf()
    {
        $this->__load();
        return parent::getLeaf();
    }

    public function setLeaf($leaf)
    {
        $this->__load();
        return parent::setLeaf($leaf);
    }

    public function getName()
    {
        $this->__load();
        return parent::getName();
    }

    public function setName($name)
    {
        $this->__load();
        return parent::setName($name);
    }

    public function getValue()
    {
        $this->__load();
        return parent::getValue();
    }

    public function setValue($value)
    {
        $this->__load();
        return parent::setValue($value);
    }

    public function getSortValue()
    {
        $this->__load();
        return parent::getSortValue();
    }

    public function setSortValue($sortValue)
    {
        $this->__load();
        return parent::setSortValue($sortValue);
    }

    public function getDisplayName()
    {
        $this->__load();
        return parent::getDisplayName();
    }

    public function setDisplayName($displayName)
    {
        $this->__load();
        return parent::setDisplayName($displayName);
    }

    public function getDisplayDesc()
    {
        $this->__load();
        return parent::getDisplayDesc();
    }

    public function setDisplayDesc($displayDesc)
    {
        $this->__load();
        return parent::setDisplayDesc($displayDesc);
    }

    public function getPath()
    {
        $this->__load();
        return parent::getPath();
    }

    public function setPath($path)
    {
        $this->__load();
        return parent::setPath($path);
    }

    public function getIPath()
    {
        $this->__load();
        return parent::getIPath();
    }

    public function setIPath($ipath)
    {
        $this->__load();
        return parent::setIPath($ipath);
    }

    public function getStatus()
    {
        $this->__load();
        return parent::getStatus();
    }

    public function setStatus($status)
    {
        $this->__load();
        return parent::setStatus($status);
    }

    public function getReflection()
    {
        $this->__load();
        return parent::getReflection();
    }

    public function offsetExists($key)
    {
        $this->__load();
        return parent::offsetExists($key);
    }

    public function offsetGet($key)
    {
        $this->__load();
        return parent::offsetGet($key);
    }

    public function offsetSet($key, $value)
    {
        $this->__load();
        return parent::offsetSet($key, $value);
    }

    public function offsetUnset($key)
    {
        $this->__load();
        return parent::offsetUnset($key);
    }

    public function toArray()
    {
        $this->__load();
        return parent::toArray();
    }

    public function merge(array $array)
    {
        $this->__load();
        return parent::merge($array);
    }

    public function offsetUnset($offset)
    {
        $this->__load();
        return parent::offsetUnset($offset);
    }

    public function offsetSet($offset, $value)
    {
        $this->__load();
        return parent::offsetSet($offset, $value);
    }

    public function offsetGet($offset)
    {
        $this->__load();
        return parent::offsetGet($offset);
    }

    public function offsetExists($offset)
    {
        $this->__load();
        return parent::offsetExists($offset);
    }


    public function __sleep()
    {
        return array('__isInitialized__', 'id', 'parent', 'children', 'locked', 'leaf', 'name', 'value', 'sortValue', 'displayName', 'displayDesc', 'path', 'ipath', 'status');
    }

    public function __clone()
    {
        if (!$this->__isInitialized__ && $this->_entityPersister) {
            $this->__isInitialized__ = true;
            $class = $this->_entityPersister->getClassMetadata();
            $original = $this->_entityPersister->load($this->_identifier);
            if ($original === null) {
                throw new \Doctrine\ORM\EntityNotFoundException();
            }
            foreach ($class->reflFields AS $field => $reflProperty) {
                $reflProperty->setValue($this, $reflProperty->getValue($original));
            }
            unset($this->_entityPersister, $this->_identifier);
        }
        
    }
}