Got this error:
$ byzanz-record-region Default recording duration 10s to /tmp/recorded.gif Delaying 3 seconds. After that, byzanz will start 3 2 1 byzanz-record: error while loading shared libraries: libgtk-3.so.0: cannot open shared object file: No such file or directory
Fixed it with:
sudo apt-get install libgtk-3-0:i386