string or binary data would be truncated using asp.net

CREATE TABLE [dbo].[Loyality1111](
[ID] [int] IDENTITY(1,1) NOT NULL primary key,
[ClientId] [int] NULL,
[CouponType] [varchar](50) NULL,
[Store] [nvarchar](15) NULL,
[CouponValueType] [varchar](50) NULL,
[CouponValue] [int] NULL,
[ValidUntil] [datetime] NULL,
[ImageName] [varchar](50) NULL,
[ImagePath] [nvarchar](max) NULL,
[CouponSentDate] [datetime] NULL,
)
At the time of inserting data through asp.net choose a image path i am getting following error:string or binary data would be truncated