Kemper clipping Problem!

Hi, yesterday during the gig my Kemper started to distort every sound, also clean sounds. Sounds like a strong digital clipping. Input and Output levels are green. Same problem on all outputs (Main, Monitor, Headphones). Updated to new OS but same problem occurs after the KPA is on for a while - problem is sometimes gone after restart. Quick help is appreciated since the next gig is on Wednesday! Thanks, Michael