Yea, those projects are fairly out of date(4.16?). I need to just re-compile them against the latest.
The Ability Editor Preview Asset flow changed in 3.0, you need to add the classes you want to use for your Preview Asset to the Able Editor Settings under “Preview Asset Allowed Classes”. Then you can just use the drop down next to the Preview Asset on the Toolbar and select the asset you want to use.
There should be no sound effects in the Machine Gun asset (or at least I don’t recall hooking it up). Again, I just need to do a pass on the examples real quick and update them. I’ll try and knock that out sometime this week.