FosUserBundle / Symfony 4 - The class was not found in the chain configured namespaces

Question

My Symfony4 app is working fine in dev environment but not in production, i can't login (using FosUserBundle). After enabling debug and profiler toolbar in production (beacause it doesn't write any log) i've found the error

The class 'App\Entity\FintelUtility\User\User' was not found in the chain configured namespaces FOS\UserBundle\Model

The class was not found in the chain configured namespaces

I've cleared the cache and i've checked mapping info of doctrine

php bin/console doctrine:mapping:info --env=prod
 Found 2 mapped entities:
 [OK]   FOS\UserBundle\Model\Group
 [OK]   FOS\UserBundle\Model\User
wwwfintel@fnt-srvweb01:~/s4fgel$ php bin/console doctrine:mapping:info --env=dev                             
 Found 5 mapped entities:
 [OK]   App\Entity\FintelUtility\QuoteOfTheDay
 [OK]   App\Entity\FintelUtility\User\Group
 [OK]   App\Entity\FintelUtility\User\User
 [OK]   FOS\UserBundle\Model\Group
 [OK]   FOS\UserBundle\Model\User

I don't know how to map those three entities that are missing.

config/packages/doctrine.yaml

# Doctrine Configuration
doctrine:
    dbal:
        default_connection: mssql_fgel_utility
        connections:
            mssql_fgel_utility:
                driver:   ~
                driver_class: "%fgelutil_database_driver_class%"
                host:     "%fgelutil_database_host%"
                dbname:   "%fgelutil_database_name%"
                user:     "%fgelutil_database_user%"
                password: "%fgelutil_database_password%"
        types:
            datetime_key: 'App\Type\DateTimeKeyType'
    orm:
        default_entity_manager: mssql_fgel_utility
        entity_managers:
            #################################
            # Update schema only with this em
            #################################
            mssql_fgel_utility:
                connection: mssql_fgel_utility
                mappings:
                    FintelUtility:
                        type:     "annotation"    
                        # The directory for entity (relative to bundle path)
                        dir:      '%kernel.project_dir%/src/Entity/FintelUtility'   
                        prefix:   'App\Entity\FintelUtility'
                        is_bundle: false

Ther's no config/packages/dev/doctrine.yaml but prod config/packages/prod/doctrine.yaml

doctrine:
    orm:
        metadata_cache_driver:
            type: service
            id: doctrine.system_cache_provider
        query_cache_driver:
            type: service
            id: doctrine.system_cache_provider
        result_cache_driver:
            type: service
            id: doctrine.result_cache_provider

services:
    doctrine.result_cache_provider:
        class: Symfony\Component\Cache\DoctrineProvider
        public: false
        arguments:
            - '@doctrine.result_cache_pool'
    doctrine.system_cache_provider:
        class: Symfony\Component\Cache\DoctrineProvider
        public: false
        arguments:
            - '@doctrine.system_cache_pool'

framework:
    cache:
        pools:
            doctrine.result_cache_pool:
                adapter: cache.app
            doctrine.system_cache_pool:
                adapter: cache.system

I've tried also php bin/console cache:warmup --env=prod --no-debug but it didn't help

Any idea?

EDIT

I've changed "mssql_fgel_utility" entity manager to "default" and it worked for prod but then it doesn't work for dev

orm:
    default_entity_manager: mssql_fgel_utility
    entity_managers:
        #################################
        # Update schema only with this em
        #################################
        # THIS WAS WRONG EVEN IF I DON'T KNOW WHY
        # mssql_fgel_utility:
        #################################
        default: #changed to this

Answer 1

I've changed "mssql_fgel_utility" entity manager to "default" and it worked

orm:
    default_entity_manager: default
    entity_managers:
        #################################
        # Update schema only with this em
        #################################
        # THIS WAS WRONG EVEN IF I DON'T KNOW WHY
        # mssql_fgel_utility:
        #################################
        default: #changed to this

Answer 2

You wrote:

I've cleared the cache and i've checked mapping info of doctrine

Is it the Symfony cache or Doctrine cache? if it's not the Doctrine cache, clear it and try the command php bin/console do:sc:va to check the mapping and check if the database is in sync with the mapping and make the php bin/console do:sc:up --force --env=prod in the case it's not in sync.

Answer 3

You have to change "mssql_fgel_utility" entity manager to "default" and delete "default_entity_manager: mssql_fgel_utility" and it will work for dev and prod.