YamlのEntity設定の中にMappingが間違えてます（CouponCouponDetail.dcm.yml）

[trebla-on]

ec-cube 3.0.12 プラグイン：Coupon 1.0.3

問題： ファイル： app/Plugin/Coupon/Resource/doctrine/Plugin.Coupon.Entity.CouponCouponDetail.dcm.yml

対応方法： 行目：29~

    manyToOne:
        Coupon:
            targetEntity: Plugin\Coupon\Entity\CouponCoupon
            inversedBy: CouponDetail
            joinColumn:
                name: coupon_id
                referencedColumnName: coupon_id
                nullable: false
        Product:
            targetEntity: Eccube\Entity\Product
            joinColumn:
                name: product_id
                referencedColumnName: product_id
                nullable: false
        Category:
            targetEntity: \Eccube\Entity\Category
            joinColumn:
                name: category_id
　　　　　　　　　　　　　　　　referencedColumnName: category_id

↓

    manyToOne:
        Coupon:　targetEntity: Plugin\Coupon\Entity\CouponCoupon
            inversedBy: CouponDetails
            joinColumn:
                name: coupon_id
                referencedColumnName: coupon_id
            nullable: false
    manyToOne:
        Product:
            targetEntity: Eccube\Entity\Product
            joinColumn:
                name: product_id
                referencedColumnName: product_id
                nullable: false
        Category:
            targetEntity: \Eccube\Entity\Category
            joinColumn:
                name: category_id
                referencedColumnName: category_id

[ryo-endo]

v.2.0.0で対応済み。