Meetoo.
After 14 months without problems and all firmware updates made, the error slowly arrived.
When booting it was frozen, so I just restarted and no problem
but this happened more and more even over several FW updates.
Then, one time the error -28 appeared in red letters.
After that I could boot again as before but I had to repeat the boot procedure more often to pass the boot screen.
Then, even it was passing the boot screen it was stopping after 5-10 minutes: no reaction and sometimes no sound at all.
Problem was evolving...so might be a hardware problem....
I was sending it back to Thomann (seller from Germany), they sent it to line6 service,
Now I have to wait without a Helix :-(
Thomann said it will take 2-3 weeks ... let’s see when I get my Helix back...
Hope that they will find the error.