I have version 0.91 of Inkscape (installed 64bit version) and xQuartz version 2.7.11.
I have used Inkscape on this computer before without problems but now it won’t load (program goes to not responding). I start xQuartz first because I read something that said I should, but that didn’t help.
I’m assuming this has to do with the OS since nothing else had changed (I don’t remember when I updated to macOS Sierra, so I’m making a wild assumption here). To be safe, I did remove and reinstall xQuartz and Inkscape (in case something had become corrupted) but that didn’t fix the problem.