Error converting varchar to numeric

[Robin25]

I check my database and all data types are correct

 conn = GetConnect()

        Dim mycommand As SqlClient.SqlCommand = New SqlClient.SqlCommand()
        mycommand.Connection = conn
        mycommand.CommandText = "Update Tbl_Member_Profile set F_Name='@F_Name', M_Name='@M_Name', L_Name='@L_Name', Date_Of_Birth='@Date_Of_Birth', Membership_Category='@Membership_Category', Age='@Age', F_Recruiter_Member_Code='@F_Recruiter_Member_Code', Credit_Rating='@Credit_Rating', Credit_Line='@Credit_Line', Credit_Limit='@Credit_Limit', Member_Photo_Data='@Member_Photo_Data' WHERE P_Member_Code='@P_Member_Code'"
        conn.Open()

        Try

            mycommand.Parameters.Add("@F_Name", SqlDbType.VarChar).Value = txt_F_Name.Text
            mycommand.Parameters.Add("@M_Name", SqlDbType.VarChar).Value = txt_M_Name.Text
            mycommand.Parameters.Add("@L_Name", SqlDbType.VarChar).Value = txt_L_Name.Text
            mycommand.Parameters.Add("@F_Recruiter_Member_Code", SqlDbType.Decimal).Value = TXT_rec_no.Text
            mycommand.Parameters.Add("@Credit_Rating", SqlDbType.Char).Value = txt_ranking.Text
            mycommand.Parameters.Add("@Membership_Category", SqlDbType.Int).Value = txt_membership.Text
            mycommand.Parameters.Add("@Credit_Line", SqlDbType.Decimal).Value = txt_cre_line.Text
            mycommand.Parameters.Add("@Credit_Limit", SqlDbType.Decimal).Value = txt_max_cre.Text
            mycommand.Parameters.Add("@Date_Of_Birth", SqlDbType.DateTime).Value = datepicker.Value.Date
            mycommand.Parameters.Add("@Age", SqlDbType.Int).Value = txt_age.Text
            mycommand.Parameters.Add("@Member_Photo_Data", SqlDbType.Image).Value = imgByteArray
            mycommand.Parameters.Add("@P_Member_Code", SqlDbType.Decimal).Value = txt_Cus_No.Text
            mycommand.ExecuteNonQuery()
            MsgBox("Success")
        Catch ex As System.Data.SqlClient.SqlException
            MsgBox(ex.Message)
        End Try

Thanks in advance

[mcupito]

Which fields in the database are numerics? Let's start there.