You can't nest {} like that in Billboard. I'll see what I can do for future versions. You can work around that by doing the checking in the script and removing the {network-name? } around it.
#!/bin/sh percent=$(qdbus --system com.nokia.csd /com/nokia/csd/csnet com.nokia.csd.CSNet.SignalStrength.SignalPercent) if [ $percent -eq -1 ]; then echo -n "{{red}}Flugmodus an ✈"; fi if [ $percent -ge 20 ]; then echo -n "{{yellow}}$percent % {{=$(($percent/100)).$((($percent%100)/10))$(($percent%10))}}"; fi if [ $percent -le 19 && -ge 1 ]; then echo -n "{{red}}$percent % {{=$(($percent/100)).$((($percent%100)/10))$(($percent%10))}}"; fi