Well, I think I’ve tampered a bit too much within my system going the way of manually adding some geoip blockings 
After I’ve updated nethserver-blacklist to v 1.2.0-1.ns7 (prior v 1.1.8-1.ns7) and enabled geoip feature according to the documentation it bailed out at
signal-event nethserver-blacklist-save geoips
In the journal, the following was logged:
Mar 17 18:59:13 redacted.my.fqdn esmith::event[15281]: /usr/share/nethserver-blacklist/download: line 38: /usr/share/nethserver-blacklist/geoip: No such file or directory
Mar 17 18:59:13 redacted.my.fqdn esmith::event[15281]: Action: /etc/e-smith/events/nethserver-blacklist-save/S20nethserver-blacklist-conf FAILED: 127 [0.23322]
However, looking at /usr/share/nethserver-blacklist/geoip
the file existed with sane content (counter-checked on a virgin nethserver)
As soon as I disabled geoip blocking in e-smith the save-event ran gratiously.
Long story short: A complete removal and reinstall afterwards of ThreadShield corrected everything and now its up and running… well country-blocking 