We\'ve just upgraded from Magento version 1.8.0.0 to 1.8.1.0 and now when we go to the configuration section of our site we receive the message:
Fatal error: Cla
Oddly I recently got this on a Magento 1.9.2.3 install.
The cause is the following missing from the app\code\core\Mage\GoogleCheckout\etc\config.xml
<global>
...
<helpers>
<googlecheckout>
<class>Mage_GoogleCheckout_Helper</class>
</googlecheckout>
</helpers>
...
</global>
Results in the autoloader not being able to find the helper file hence reverting to checking for Mage_Googlecheckout.
If you will delete files then google checkout will not work.
I found this answer useful.
<helpers>
<googlecheckout>
<class>Mage_GoogleCheckout_Helper</class>
</googlecheckout>
</helpers>