Since 3.5 there has been quite a few significant changes, especially at version 3.8. Which unfortunately makes it somewhat tedious to do an upgrade from 3.50 to the latest version. Some items have name changes and others have been moved to different namespaces.
If you are familiar with .NET and namespaces, it is not too terribly difficult, just time consuming. I recently did a similar upgrade and it took me about 30 minutes with a lot of Search and Replace.
You can start by opening a fresh copy of the latest version, then right click the AdvancedHMI project in Solution Explorer, and selecting Add->Existing Item. The browse to your main form in your older version. Once that form is added, take a look at the errors you get.
For example you may see something like BasicLabel control not found. Open yet another fresh copy of the latest version, then add a BasicLabel to it. You can then examine the .designer.vb code behind the form to see what name changing has occured. After a doing this with a couple items, you will see the name change pattern which can be used for Search and Replace.