Ubuntu 16.04: simple-scan I/O error
At the time of writing this, these 3 packages need to be downloaded and installed.
libsane-common_1.0.26~git20151121-1_all.deb
libsane_1.0.26~git20151121-1_amd64.deb
libjpeg62-turbo_1.5.1-1_amd64.deb
The first two packages can be found in the Debian experimental libs at this link https://packages.debian.org/experimental/libs/
The last package I found in this link https://packages.debian.org/sid/libjpeg62-turbo
In some cases you may need to navigate to an ftp mirror site to actually download.
Once downloaded, simply install each package as root i.e
sudo dpkg -i package
I have tested with simple-scan, xsane, and scangearmp and all works fine.