Mapping Exception : Class does not exist Symfony2 Deployment - symfony

Question

I have a working Project on localhost but when I deployed the project I received this error and I have no idea what's causing this to happen.
MappingException: Class 'PremiumPharma\SystemBundle\Entity\User' does not exist
this is the stacktrace
in /home/sy2/public_html/temp/symfony/vendor/doctrine/common/lib/Doctrine/Common/Persistence/Mapping/MappingException.php line 96
at MappingException::nonExistingClass('PremiumPharma\SystemBundle\Entity\User') in /home/sy2/public_html/temp/symfony/vendor/doctrine/common/lib/Doctrine/Common/Persistence/Mapping/RuntimeReflectionService.php line 43
at RuntimeReflectionService->getParentClasses('PremiumPharma\SystemBundle\Entity\User') in /home/sy2/public_html/temp/symfony/vendor/doctrine/common/lib/Doctrine/Common/Persistence/Mapping/AbstractClassMetadataFactory.php line 267
Edit 1
I did notice some errors in the profiler as it said 5 invalid entities and there were some mapping errors and I got them fixed. After re-uploading I still have the same issue. I also tried to empty the cache but I still receive the same error.
Edit 2
here is my appKernal
<?php
use Symfony\Component\HttpKernel\Kernel;
use Symfony\Component\Config\Loader\LoaderInterface;
class AppKernel extends Kernel
{
public function registerBundles()
{
$bundles = array(
new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
new Symfony\Bundle\SecurityBundle\SecurityBundle(),
new Symfony\Bundle\TwigBundle\TwigBundle(),
new Symfony\Bundle\MonologBundle\MonologBundle(),
new Symfony\Bundle\SwiftmailerBundle\SwiftmailerBundle(),
new Symfony\Bundle\AsseticBundle\AsseticBundle(),
new Doctrine\Bundle\DoctrineBundle\DoctrineBundle(),
new Sensio\Bundle\FrameworkExtraBundle\SensioFrameworkExtraBundle(),
new PremiumPharma\SystemBundle\PremiumPharmaSystemBundle(),
new FOS\UserBundle\FOSUserBundle(),
);
if (in_array($this->getEnvironment(), array('dev', 'test'))) {
$bundles[] = new Acme\DemoBundle\AcmeDemoBundle();
$bundles[] = new Symfony\Bundle\WebProfilerBundle\WebProfilerBundle();
$bundles[] = new Sensio\Bundle\DistributionBundle\SensioDistributionBundle();
$bundles[] = new Sensio\Bundle\GeneratorBundle\SensioGeneratorBundle();
}
return $bundles;
}
public function registerContainerConfiguration(LoaderInterface $loader)
{
$loader->load(__DIR__.'/config/config_'.$this->getEnvironment().'.yml');
}
}
Edit 3
As per J.Mose last comment it was a unix/windows conflict as my local machine was windows and the server was Unix. I had to rename all files to match exactly the classname.

Answer 1

Did you deploy an older version on this environment ?
If yes, did you delete all application's files before deploying ? If an older version of an entity doesn't exist in your project anymore (or renamed), it can provoke that kind of mapping error.
Alternatively, check in your AppKernel.php if the bundle with the entity is enabled on all environnment.
Further, if application is deployed on a Unix environnement (against a local Windows), check if your entity's name is exactly the same as the php file (cause Windows is case insensitive)

Answer 2

this problem has just happened to me and i have fixed it by adding the vendor name to the directory path in the config.yml file.
Step 5: Configure the FOSUserBundle
app/config/config.yml
fos_user:
db_driver: orm # other valid values are 'mongodb', 'couchdb' and 'propel'
firewall_name: main
user_class: AppBundle\Entity\User
change the appBundle to Vendor\NameofYourBundle\Entity\User

Answer 3

This error was show me when I used EasyAdminBundle and FOSUserBundle with Symfony 3.3.x .
The solution is simple:
First is necessary verification app/config/config.yml in my case the error was the name of the Bundle:
fos_user:
db_driver: orm # other valid values are 'mongodb' and 'couchdb'
firewall_name: main
user_class: BackendBundle\Entity\User
And after clean of cache:
php bin/console cache:warmup
This was my solution