[fixed] Firefox only 500 internal Server error on Module pages

[FlALo]

Hi everyone

I have an interesting case where I would love to hear oppinions and ideas towards a solution:

On my Presta 1.7 instance on www.lorisvelos.ch, a strange error occurs. I noticed it on two completely independent module pages thus far, and it only appears in Firefox browsers and only on about 8/10 computers (independent of Firefox version or OS). I mean that, I tested it on serveral machines, on two it did not throw the errors, on the others it did.

The pages where it occurs are:

1. https://lorisvelos.ch/Galerie (If you click on a picture, then if fails to load in the name of the account in the top)

2. https://lorisvelos.ch/module/supercheckout/supercheckout (appears right away accessing page, failing to load in cart, carriers and payment options)

I attached screen shots of the console error of both pages.

 

Server-side, the error log  for both instances reads like this:

Quote

[STDERR] PHP Fatal error: Uncaught Error: Call to a member function query() on null in XXX/XXX/public_html/lorisvelos.ch/classes/db/DbPDO.php:165

With Debug-Mode activated:

Quote

[STDERR] PHP Fatal error: Uncaught Symfony\Component\Debug\Exception\ContextErrorException: Notice: Undefined property: DbPDO::$link in XXX/XXX/public_html/lorisvelos.ch/classes/db/DbPDO.php:165

 

This is line 165 in dbPDO.php:

    /**
     * Executes an SQL statement, returning a result set as a PDOStatement object or true/false.
     *
     * @see DbCore::_query()
     *
     * @param string $sql
     *
     * @return PDOStatement
     */
    protected function _query($sql)
    {
        return $this->link->query($sql);
    }

    /**

 

Originally I thought the error might be in the modules, but as the two completely unrelated modules throw the exact same one, it has to be a central issue. I found it to occur "only" on these two modules thus far.

Any Ideas?

 

Thank you in advance

Florian

 

 

 

*********************************************************************************************************************

FIXED!

After trying everything, I disabled an external cache module calles Litespeedcache.

After disabling it, the error went away.

 

Edited July 24, 2021 by FlALo
Fixed! (see edit history)