Share 'A real bug in C#!!!!!'

Because there isnot debug in grasshopper,i find the mistake by creat variables. my total code is 230 rows,but the outputshow there is a error in 242 row! i cannot believe that! when i delete the "curb" input of the c# component,the error is disappera! i think it should be a bug!(i attach the zip,you can check it)