Question about NilObjectException

I am a newbie in xojo, I purchased the Desktop version for Windows (2015r1) and my os is W8.1x64. Now I am experiencing writing a program for contacts. I have build the program and the build is working fine in my pc. I have test the same build in another pc with Windows 7 x64 and in a Virtual Machine with same os, but in the other computer and in vm the program doesen’t start with error: "An exception of class NilObjectException was not handled …
What I make wrong ?. Is my exe (with libs folder) really stand alone.
How I can debug my application ?

Install the remote debugger on a Win 7 machine :slight_smile:

It is. However, you are probably trying to access some resource, such as a file or database, that doesn’t exist on the other machines, and you don’t have sufficient error checking in place to prevent the crash or inform you of the problem.

Thank you I will execute some tests.