manolito, thank you for your help.
I experience similar problems like Ian_J (Error Message: 'Warning! Title 1 output Video duration (00:00:00) is shorter than expected duration.') and switching from HCEnc to ffmpeg solved my problem.
What seems to be interesting - I have two machines, one with Win 10 the other with Win 7 (fresh install, I went back from Win 10 to Win 7 due to lacking drivers) and both started to have the problems after LAV filters update (from v. 0.66 to v 0.67). Coincidence? I do not know. I swear I have no problems with cooling the CPUs of the machines, as well as I did not touch HCEnc.