Ok, today has now escalated into officially one of those days.
Updated to the newest firmware the other day. Today I went to plug the main left into my maudio sound card and as loud pop happened.
Long story short. Goodbye krk rokits... Goodbye msi titan gt63 laptop.
Couldn't figure out what it was, thought I'd try plugging the main out into another guitar amp. Another huge pop and now the kemper is dead too.
Support has been contacted, unit is 2 or 3 years old. Laptop is 4 months out of warranty.
Be careful what you plug into.