ARIA is currently in a bit of a state. Ideally, you want to use the VST3 plug-ins, if possible. Steinberg deprecated VST2 over 10 years ago, and is likely to drop their use entirely at some point.
If you’re on an Apple Silicon Mac, then you need to install the 2.0.26 ARIA player and plug-ins from MakeMusic’s support site.
If you’re on Windows, the latest version is 1.959, which you can get here.
ARIA Player 1.959.
I’d also recommend installing the Sforzando Player from Plogue (the people who made ARIA for MM), as this will update the ‘engine’ that ARIA Player uses to 1.978.
(I’d also recommend that Mac users install the 1.978 engine, because MM’s 2.026 player actually still uses the 1.959 engine!! And the version numbering disparity means that Mac and Windows can’t share setups. But I digress.)
I’ve created a Playback template for GPO5 here. (It requires the 1.978 engine.) There’s also as much copious information about ARIA as I could find.
Oooh: thanks for the info about EWI USB. While the samples are unlikely to be anything that isn’t already in the other Garritan packages, having a PNG licence for an additional bank is always useful…!!!