There are two error outputs (with a bunch of warnings) in the console that might be relevant:
Error: Promised response from onMessage listener went out of scope 3 background.js:931:170
and
Cross-Origin request blocked
I tried to run it on an old Linux laptop (Debian 8, can't use newer because of old ATi graphics and fglrx driver) and it failed with the following output: https://pastebin.com/6nsZRKkn