Fingerprint identification FP4

cannot suceed with installing the fingerprint identification on my fairphone (german:)
“Zeitüberschreitung bei Fingerdruckeinrichtung Fehler bei Fingerdruckregistrierung. Versuche es erneut oder verwende einen anderen Finger”
I tried all my ten fingers, always the same

And you followed the “instructions”, i.e. you put the finger on the sensor, lift it, put it back on etc till the system has “filled” all lines?

yes, of course,i did

To be exact, the error comes after I put the finger on the sensor.
and I tried at least 15 times