hplip crashes when installing a hp laser printer M 15w

I'm on ubuntu 16.4 and have an updated and upgraded hplip and hplip-gui installed. Now, I try to install a hp laser printer M 15w.

The setup routine finds a printer but crashes with the traceback:

Traceback (most recent call last):
  File "/usr/share/hplip/ui5/wifisetupdialog.py", line 754, in NextButton_clicked
    self.showExitPage()
  File "/usr/share/hplip/ui5/wifisetupdialog.py", line 573, in showExitPage
    self.ip, subnetmask, gateway, pri_dns, sec_dns, addressmode = self.wifiobj.getwifiotherdetails(self.dev,self.adapterName)
AttributeError: 'WifiSetupDialog' object has no attribute 'wifiobj'

This happens just before completing the installation process.

The command

apt-cache policy hplip hplip-data; python3 -V; python -V 

gives:

hplip:
  Installiert:           3.17.10+repack0-5
  Installationskandidat: 3.17.10+repack0-5
  Versionstabelle:
 *** 3.17.10+repack0-5 500
        500 http://de.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status
hplip-data:
  Installiert:           3.17.10+repack0-5
  Installationskandidat: 3.17.10+repack0-5
  Versionstabelle:
 *** 3.17.10+repack0-5 500
        500 http://de.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        500 http://de.archive.ubuntu.com/ubuntu bionic/main i386 Packages
        100 /var/lib/dpkg/status
Python 3.6.9
Python 2.7.17