Hi. I'm trying to set up a web application in Laravel 5.1 that uses queued jobs, using the database driver and MySQL as the database. I have the application working fine on a single CentOS server, but now I want to set up the configuration so that the jobs are pushed onto the queue on the CentOS machine, and then processed on a completely separate Ubuntu machine.

So far, I've gotten jobs to be pushed on one machine into the database. Then I set up my Ubuntu server with a copy of the site, and a listener running on the same database. However, when the listener tries to process the job, I get the error:

local.ERROR: exception 'InvalidArgumentException' with message 'No handler registered for command [__PHP_Incomplete_Class]' in [site-directory]/vendor/laravel/framework/src/Illuminate/Bus/Dispatcher.php:334

From what I've seen about __PHP_Incomplete_Class, this might have something to do with session mismatching, but I'm not really sure at this point. Does anyone have any suggestions about what might be causing this, and how to get around it?