解决办法 ：参考
https://stackoverflow.com/questions/33160729/magento-events-giving-error-warning-includemage-modulename-model-observer-php

将 下面代码

<class>modulename/observer</class>

改成：

<class>Namespace_Modulename_Model_Observer</class>

 <events>
            <adminhtml_sales_order_create_process_data>
                <observers>
                    <Createorder>>
                        <type>singleton</type>
                        <class>Lollicupstore_Createorder_Model_Observer</class>
                        <method>saveCustomData</method>
                    </Createorder>>
                </observers>
            </adminhtml_sales_order_create_process_data>
        </events>