Fatal error: Call to a member function beginTransaction() on boolean in /var/www/html/app/code/core/Mage/Core/Model/Abstract.php on line 313

Question

I'm getting the following error after moving a Magento 1.9.1 project from my local Vagrant box to a remote server:

Fatal error: Call to a member function beginTransaction() on boolean in /var/www/html/app/code/core/Mage/Core/Model/Abstract.php on line 313

This errors points to this section of code:

$this->_getResource()->beginTransaction();

Where $this->_getResource is returning false. This seems to be caused by either a Model autoloading issue, or models not getting initialized correctly but I cannot find the cause.

The app has no errors locally, and I don't see any major differences between my server environment and local environment. Here are the config files and model files that are relevant to the problem

config.xml

<models>
    <company_xmpieformbuilder>
        <class>Company_XMPieFormBuilder_Model</class>
        <resourceModel>xmpieformbuilder_resource</resourceModel>
    </company_xmpieformbuilder>
    <xmpieformbuilder_resource>
        <class>Company_XMPieFormBuilder_Model_Resource</class>
        <entities>
            <configuration>
                <table>company_xmpieformbuilder_configuration</table>
            </configuration>
            <fieldset>
                <table>company_xmpieformbuilder_fieldset</table>
            </fieldset>
            <field>
                <table>company_xmpieformbuilder_field</table>
            </field>
            <fieldtype>
                <table>company_xmpieformbuilder_field_type</table>
            </fieldtype>
            <fieldinputcontrol>
                <table>company_xmpieformbuilder_field_input_control</table>
            </fieldinputcontrol>
            <fieldattributes>
                <table>company_xmpieformbuilder_field_attributes</table>
            </fieldattributes>
            <fieldpossiblevalues>
                <table>company_xmpieformbuilder_field_possible_values</table>
            </fieldpossiblevalues>
            <fieldrule>
                <table>company_xmpieformbuilder_field_rule</table>
            </fieldrule>
            <fieldruletype>
                <table>company_xmpieformbuilder_field_rule_type</table>
            </fieldruletype>
            <fieldvaluesource>
                <table>company_xmpieformbuilder_field_value_source</table>
            </fieldvaluesource>
        </entities>
    </xmpieformbuilder_resource>
    <core>
        <rewrite>
            <abstract_model>Company_Core_Model_Abstract</abstract_model>
        </rewrite>
    </core>
    <catalog>
        <rewrite>
            <product>Company_Catalog_Model_Product</product>            
        </rewrite>
    </catalog>
</models>

Example model, all the models are empty similar to this.

class Company_XMPieFormBuilder_Model_Configuration extends Company_Core_Model_Abstract {

    protected function _construct()
    {
        $this->_init('company_xmpieformbuilder/configuration');
    }

}

Base model.

class Company_Core_Model_Abstract extends Mage_Core_Model_Abstract {
}

Answer 1

The problem comes from the declaration of the resources and the name used in the models.

So instead of :

<xmpieformbuilder>
    <class>Company_XMPieFormBuilder_Model</class>
    <resourceModel>xmpieformbuilder_resource</resourceModel>
</xmpieformbuilder>

And then in your models you need to call:

$this->_init('xmpieformbuilder/configuration');

That comes from the fact that you declares your entities using the xmpieformbuilder_resource tag.