How to solve this error

make a break point on this particular line

SqlCommand cmdExecute = new SqlCommand("insert into tbl1 (column_name) values(value)",con);

inspect the actual SQL Statement that is getting fired from the .NET Code, by using watch window or anything like that...and if still not got the error copy the SQL From the watch window and paste it in the SQL Server query analyzer to find the actual error....

foreach (KeyValuePair<string, object> kvp in parameters)
            {
                column_name =kvp.Key+",";
                value = kvp.Key + ";";
                SqlCommand cmdExecute = new SqlCommand("insert into tbl1 (column_name) values(value)",con);
                return cmdExecute.ExecuteNonQuery();
            }

public static int Dynamicarray(string connectionString, Dictionary<string,object> parameters)
    {
        using (SqlConnection con = Database.GetConnection())
        {
 
            string column_name;
            string value;
            foreach (KeyValuePair<string,object> kvp in parameters)
            {
                column_name =kvp.Key+",";
                value = kvp.Value.ToString()+ ",";
                //cmdExecute.Parameters.AddWithValue(kvp.Key, kvp.Value);
            }
            column_name = column_name.Remove(column_name.LastIndexOf(","));
            value = value.Remove(value .LastIndexOf(","));
            SqlCommand cmdExecute = new SqlCommand("insert into tbl1 ("+column_name+") values("+ value+ ")",con);
            //cmdExecute.CommandType = System.Data.CommandType.StoredProcedure;
            //con.Open();
            return cmdExecute.ExecuteNonQuery();
        }
    }.

haven't tested, please fix if you find any typo's
hope this helps