https://bugs.winehq.org/show_bug.cgi?id=50221
--- Comment #9 from Serge Y. Stroobandt serge@stroobandt.com --- Excellent, Olivier!
sudo apt install libjpeg62 libjpeg62:i386
indeed solved all my issues.
4nec2 now runs fine with PlayOnLinux 4.3.4 and 64-bit wine version 5.19 on (X)Ubuntu LTS 20.04
Thank you for all your kind suggestions.
Suggestion: Perhaps, it might be worthwhile to make wine dependent on these legacy JPEG library packages.