Ojs\CmsBundle\Entity\File:
    type: entity
    table: file
    repositoryClass: Ojs\CmsBundle\Entity\FileRepository
    inheritanceType: SINGLE_TABLE
    discriminatorColumn:
        name: discriminator
        type: string
    discriminatorMap:
        admin: Ojs\AdminBundle\Entity\AdminFile
        journal: Ojs\JournalBundle\Entity\JournalFile
    id:
        id:
            type: integer
            id: true
            generator:
                strategy: AUTO
    fields:
        name:
           type: string
           length: 255
        description:
            type: text
        path:
            type: text
        size:
           type: string
           length: 255
        tags:
            type: string
            length: 255

    lifecycleCallbacks: {  }

Ojs\CmsBundle\Entity\File:
    type: entity
    table: file
    repositoryClass: Ojs\CmsBundle\Entity\FileRepository
    inheritanceType: SINGLE_TABLE
    discriminatorColumn:
        name: discriminator
        type: string
    discriminatorMap:
        admin: Ojs\AdminBundle\Entity\AdminFile
        journal: Ojs\JournalBundle\Entity\JournalFile
    id:
        id:
            type: integer
            id: true
            generator:
                strategy: AUTO
    fields:
        name:
            type: string
            length: 255
        description:
            type: text
            nullable: true
        path:
            type: text
        size:
            type: string
            length: 255
        tags:
            type: string
            length: 255
            nullable: true

    lifecycleCallbacks: {  }

Correct indentation, make description nullable
Correct indentation, make description nullable
