Error in config after extension installation

[ethantram]

Hello,

After installing an extension, in this case, CDR - Order Comment (http://www.magentocommerce.com/magento-connect/cdr-order-comment.html) I get an error message when I go to system > configuration with the message displayed being:

Fatal error: Class 'Cdr_OrderComment_Helper_Data' not found in /home/shop/public_html/app/Mage.php on line 547

It get a similar error message when trying to install another extension so I don't think the issue is related to the extension - this only seemed to happen after installing the most recent security patches as didn't have any problems installing extensions before

I am running Magento Comuunity v1.9 I have installed pagayo_pt001, Sitewards_B2BProfessional and ext4mage_orders2csv.

Any advice greatly appreciated as usual, thanks in advance.

[iweb_p3mbo]

Hi,

Can you try clearing the cache manually (removing contents of the var/cache/ folder) and then trying again?

If this doesnt help - I would advise contacting the plugin creator and asking them for assistance since this error usually points to the plugin not having a Helper that is required at some points in the admin.

[iweb_smartie]

Just to add to what @iweb_p3mbo has said which i also believe to be true, make sure you have compliation disabled as well. It sounds like Magento is just not aware of this module yet which will be resolved once the config cache is rebuilt.

[ethantram]

Thank you both for your suggestions, I have cleared the cache manually as recommended but still experience the error as described.  I'm not sure how to diable compilation as I couldn't see this option in the connect manager settings?

I did contact the developer of the extension before posting on the forum, but didn't get a response - I can only assume it is not supported anymore or not for Magento CE versions.  Looking around the line where the error occurs, it seems to revolve around the helper function:

public static function helper($name)
{
$registryKey = '_helper/' . $name;
if (!self::registry($registryKey)) {
$helperClass = self::getConfig()->getHelperClassName($name);
self::register($registryKey, new $helperClass);
}
return self::registry($registryKey);
}

I tried to install another extension but ran into another error message which has led me to believe there is  probelm with my Magento core rather than a specific extension

[iweb_smartie · Accepted solution]

Hi @ethantram

The error does not point to an issue with core. This is the global method for retrieving the helper classes associated with a module. You can check if compilation is enabled or not by going to System > Tools > Compilation page

Regards,

Andy

[ethantram]

Hi @iweb_smartie

I turned off compilation and was able to install the extension which is brilliant - do you know if there are any repercussions for turning compilation off? I wondering, not that I've installed the extension, I'll be able to turn compilation back on!

I will be accepting your your suggegstion of turning off compilation as the answer.

Thanks for everyone's help (what a great community)

[iweb_smartie]

Hi @ethantram

In my opinion i would turn it back on.

There is however a lot of differing views as to how much performance is gained from having it turned on but as long as you remember to turn it off / recompile after making changes like installing modules you will be fine.

Regards,

Andy