PS: I can kill the process without problem from command line using taskkill /f /im
Using latest wyBuild version, when an update is performed, wyBuild detects that our app is still running and needs to be shut down. And this even if I added an Update Action. Furthermore, having my application 2 instances called with the same name, when the user press the wyBuild button to force shut down. Only one of the 2 instances is killed. Anything that can be done on the site of wyBuild?
Well, this entirely up to you. This is an app logic problem. If you allow multiple instances of your app and the customer want to update them they either have to close all instances of the app, you have to do it, or wyUpdate prompts them to do it.
If you never want to see wyUpdate prompt the user to close your app, then you need to close your app. Otherwise, just use wyUpdate as designed.