Glitch Report
2nd UPDATE
In this case, when Sonitus Reverb's AUX: Vocal Hall 2 - Predelay is set somewhere between 105-250 ms and DRY set to 0, it overloads the Mackie ASIO with a crackling pop permanently pegging the buss's meters whenever it's ON and killing all audio. It works fine below 105. No audio needs to pass thru the reverb for this to happen. It's intermittent so not 100% reproduceable and only seems to happen with this preset and Mackie Onyx. Never happened with any other interfaces.
Removing and replacing the reverb and the bus does not fix it. So far the only fix is to keep Predelay at or below 105.
Windows 10 Home, i7 Intel, 32 GB ram, SSD OS & storage drives, Mackie Onyx 12 interface.