I've edited (using WinSCP) /etc/pihole/setupVars.conf, to make the modifications, required for the installation of DNScrypt
It's not entirely clear when to add a line feed to the end of a unix file. I've seen github file changes in the pihole repository that explicitly remove the line feed at the end of a file, but obviously, an extra line feed seems to be required for setupVars.conf.
I suppose the problem occurred after I've updated from v2.11 to v2.11.1 (setupVars.conf rewritten by the installation program?)
additional question: can I delete setupVars.conf.bak and setupVars.conf.update.bak, or are they required for future updates?