Tvheadend

Hey, I wanted to ask you for help. I don't know if this is bug to report.

I am using latest 4.3-1776~g717030b on my Debian server. At the same time it runs over 20 channels (mostly recording 24/7) I noticed that after around 20 hours of running this appears in log

Unable to generate challenge

than after few minutes this started to happened

iptv: Unable to start pipe 'pipe:///home/media/ffmpeg -loglevel fatal -i INPUT -map 0 -codec copy -f mpegts pipe:1' (wrong executable?)

and after that TVH Servers is restarted. No crush is reported. But streaming and recording is stopped. When I was using stable version I didn't have this errors.

Do you have any ideas what could help me?