PHP Fatal error: Internal Zend error - Missing class information

My customer has started receiving the following errors in the server log:

PHP Fatal error: Internal Zend error - Missing class information for in /var/www/vhosts/domain.com/httpdocs/includes/classes/class.base.php on line 20

Their site is running 1.3.9d with a boatload of mods installed. I've tried to find information on this error but haven't anything related to ZC. Any suggestions?

In the original code, Line 20 of class.base.php is a line of comment text. So it doesn't make sense that any error message would trigger on that line at all.

You'll need to work with your hosting company to fix their server's Zend problem (Zend Optimizer is part of the PHP engine, and is probably what's reporting your error).

And maybe you've got corrupt files on your server?
At the very least you're using outdated code. No good reason not to upgrade.

Moving this out of the Bug Reports section, because it's not a Zen Cart bug.

Thanks for that info. I'll need to try and understand why they made a change to that file. There's been a lot of chefs stirring the pot on this site for a while.