一条普通的查询偶发Collection was modified;错误 返回

System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
  at System.Collections.Generic.List`1.Enumerator.MoveNextRare()
  at System.Linq.Enumerable.WhereListIterator`1.MoveNext()
  at System.Linq.Enumerable.Any[TSource](IEnumerable`1 source, Func`2 predicate)
  at SqlSugar.SqlSugarProvider.InitMappingInfo(EntityInfo entityInfo)
  at SqlSugar.SqlSugarProvider.InitMappingInfo(Type type)
  at SqlSugar.SqlSugarProvider.InitMappingInfo[T]()
  at SqlSugar.SqlSugarProvider.Queryable[T]()
  at SqlSugar.SqlSugarClient.Queryable[T]()

业务代码如下：

            int result = SqlSugarUtil.GetSqlSugarClient()
                .Queryable<CommunityDoctorDto>()
                .Where(t => t.Code == doctorCode)
                .Count();
            return result > 0;

数据库配置如下：

if (instance == null)
                    {
                        instance = new SqlSugarClient(
                            new ConnectionConfig()
                            {
                                ConnectionString = DBConnectionString,
                                DbType = SqlSugar.DbType.MySql,   // 设置数据库类型
                                IsAutoCloseConnection = true,   // 自动释放数据务,如果存在事务,在事务结束后释放.
                                InitKeyType = InitKeyType.Attribute   // 从实体特性中读取主键自增列信息
                            });

                        instance.Ado.CommandTimeOut = 30000;   // 设置超时时间
                        instance.Aop.OnLogExecuted = (sql, pars) => { };

                        // SQL执行完事件
                        instance.Aop.OnLogExecuting = (sql, pars) =>
                        {
                            //Console.WriteLine(sql);
                        };   // SQL执行前事件

                        // 执行SQL错误事件
                        instance.Aop.OnError = (ex) => throw new Exception(ex.Message);

                        // SQL执行前可以修改SQL
                        instance.Aop.OnExecutingChangeSql = (sql, pars) => new KeyValuePair<string, SugarParameter[]>(sql, pars);
                    }