Here's a strange one. I was playing a gig when for no reason my D string died and my Helix froze. I rebooted my Helix but my D string was still dead.
I perservered playing three string solos whilst swearing under my breath for the rest of the gig!
When I got home I hooked up my JTV with my Helix and it had "fixed" itself. So I thought I would "reflash" my JTV with workbench. What I found was my Strat in position 4 had, had it's output raised by 1db! I readjusted it to normal. At my next gig everything was normal. My question is could a power spike have happened that I did not notice have caused this?