How to read VPP?

I’m using SDE for .NET
I try to open a old vpp file double cliking, but it does not work!?
how can I read a VPP files not coming from the same VS.Net Project?

Dear Franklin,

Thank you for your message and we are sorry for any inconvenience this problem caused you. Could you mind send me your project file for investigation? You can send to or to my private message box. Thanks in advance!

Best regards,