Csharp 在 EF Core 代码优先中运行 AddMigration 时出现错误

我在网上搜索了很多次，也在聊天中问了很多问题，但我找不到答案.当我运行add-migration时出现错误:

无法从实体类型""DataLayer.Models.QuizModel(Dictionary&lt；String，Object&>)""中删除属性""quizType""，因为它正被用于""DataLayer.Models.QuizModel(Dictionary&lt；字符串，Object&>)""的外键""quizType"".""必须先移除或重新定义包含外键的所有内容，然后才能移除该属性.

但我没有删除任何东西，我认为错误是错误的.这是我的测验环境和我的模型:

namespace DataLayer.Models
{ 
    public class QuizType
    {
        [Key]
        [Required]
        public int quizType { get; set; }

        [MaxLength(150)]
        public string QuizTitle { get; set; }

        public QuizModel quizModel { get; set; }
    }
}

UserModel:

namespace DataLayer.Models
{
    public class UserModel
    {
        [Key]
        [Required]
        public int UserID { get; set; }

        [Required]
        [MaxLength(300)]
        public string UserName { get; set; }

        [Required]
        [MaxLength(300)]
        public string Password { get; set; }

        [AllowNull]
        [MaxLength(150)]
        public string Role { get; set; }

        public ICollection<QuizModel> quizes { get; set; }
    }
}

QuizModel:

namespace DataLayer.Models
{
    public class QuizModel
    {
        [Key]
        [Required]
        public int QuizID { get; set; }

        [Required]
        [MaxLength(150)]
        public string QuizName { get; set; }

        [Required]
        [MaxLength(300)]
        public string Categories { get; set; }

        [Required]
        public int QuestionCount { get; set; }

        [Required]
        public int QuizType { get; set; }

        [ForeignKey("QuizType")]
        public QuizType quizType { get; set; }

        [Required]
        [ForeignKey("User")]
        public int UserID { get; set; }

        public UserModel User { get; set; }

        public ICollection<QuestionModel> Questions { get; set; }
    }
}

QuestionModel:

namespace DataLayer.Models
{
    public class QuestionModel
    {
        [Key]
        [Required]
        public int QuestionID { get; set; }

        [Required]
        [MaxLength(400)]
        public string QuestionText { get; set; }

        [Required]
        public int QuizType{ get; set; }

        [ForeignKey(name:"quiz")]
        public int QuizID { get; set; }

        public QuizModel quiz { get; set; } 

        public AnswerModel Answer { get; set; }

        public ICollection<AnswerOption> Oprtions { get; set; }
    }
}

AnswerModel班和AnswerOption班:

namespace DataLayer.Models
{
    public class AnswerModel
    {
        [Key]
        [Required]
        public int AnswerID { get; set; }

        [Required]
        [MaxLength(300)]
        public string Answertxt { get; set; }

        [Required]
        [ForeignKey(name: "Question")]
        public int QuestionID { get; set; }

        public QuestionModel Question { get; set; }

        [Required]
        public bool AnswerValidation { get; set; }
    }

    public class AnswerOption
    {
        [Key]
        [Required]
        public int OptionID { get; set; }

        [Required]
        [MaxLength(300)]
        public string Optiontxt { get; set; }

        [Required]
        public bool answerValidation { get; set; }

        [Required]
        [ForeignKey(name: "questionModel")]
        public int QuestionID { get; set; }

        public QuestionModel questionModel { get; set; }
    }
}