The bugreport is solved by:
zypper remove hplip-sane libsane1 sane-backends sane-backends-autoconfigdoing a reboot, than installing it again together with hplip as suggested from zypper:
zypper install hplip hplip-sane libsane1 sane-backends sane-backends-autoconfig
Have you done this? Also deleting sane?