I had a replicable error recently.  Using the vst 3 Waves API suite - Stereo EQ - and Stereo Comp on a bass aux track - I wanted to add a 3rd vst 3 compressor to do some sidechaining - and I chose my trusty Izotope Alloy 2.  Splat lost the audio engine and produced feedback through the aux track immediately upon insertion.   I had to close out and re-open splat.  
 
Has anyone else experienced any of this?

FWIW I use Alloy in my vocal chain most of the time and also in the chain I use the waves API. Haven't had that issue that you are speaking of.