I tried with System!k extension: didn't work either
but thanks for the idea. So I tried "lipc-set-prop com.lab126.ota startUpdate 1" manually in xterm and got "com.lab126.ota failed to set value for property startUpdate (0x3 lipcErrNoSuchSource)"
On the 411 page is written
"2.4 OTA State: OTA Current"
"2.5 Available OTA Version: -1"
Any further hints.
One thing I might mention is that I tried to restart framework and restart (without the *.bin file present) several times without any luck. Furthermore, I first didn't find the "https://github.com/chrox/KPVBooklet/downloads" and thus tried to compile the *.bin file myself but it was also grayed out.