I added tags to this post to increase visibility.
"Object reference not set to an instance of an object" is a very common error message related to the Microsoft .NET Framework and can be triggered for all sorts of possible reasons. We would need more information before we being to troubleshoot this error.
When does this error occur? Is it when you try to perform a specific function/task in the software? How reproducible is the error?
Since there has not been any activity on this post in quite some time, I have marked it as "Assumed Answered". Please let us know if you still require any further assistance and we can pick up from there.