I installed from zesty-desktop-i386.iso (without fetching any proprietary packages). After rebooting into the installed system I could install flashplugin-installer (and the whole lubuntu-restricted-extras).
It seems this bug affects only the installation of Lubuntu itself, or maybe it is depending on the hardware. I installed in http://www.toshiba.se/laptops/satellite-pro/c850/satellite-pro-c850-19w/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1682031 Title: adobe flashplugin could not be installed in lubuntu 17.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/adobe-flashplugin/+bug/1682031/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs