Comment 13 for bug 1638373

As a workaround I downloaded libpoppler58 .deb and the libpng12 .deb which it required, then put them in the same folder and ran from that folder in terminal...

sudo dpkg -i libpoppler58_0.41.0-0ubuntu1.1_i386.deb libpng12-0_1.2.54-1ubuntu1_i386.deb

...before attempting to install Inkscape stable again which succeeded.

Please note, my architecture is i386 and yours may be different, so download the correct matching .debs for your platform. I searched for Xenial packages in each case.

Seems libpoppler58 can live alongside libpoppler61 if necessary - nothing needed to be downgraded or uninstalled that I could see and Inkscape stable seemed to launch and run OK after this.