facing issue in NA VRP C# code customization

I have downloaded Csharp sample code for VRP from SDk help


I wanted to add just one extra parameter say(Cost) which has time unit and analyze the same network.

Problem Faced :

1. When I tried adding one more attribute "Cost" (Usage typ///) value= minutes, I get an exception "Input string is not in a correct format"

2. When I change distance unit attribute from mile to meter I get exception "No Orders Routed"

Please do help.

Thanks.