document.createRange is not a function

[xtuc]

From our frontend JavaScript tracker:

TypeError: document.createRange is not a function
File https://contributor.ninja/static/js/main.098f5c9b.js line 1 col 476796 in f
File https://contributor.ninja/static/js/main.098f5c9b.js line 1 col 480406 in C
File https://contributor.ninja/static/js/main.098f5c9b.js line 1 col 481672 in e.R
File https://contributor.ninja/static/js/main.098f5c9b.js line 1 col 494056 in e.value
File https://contributor.ninja/static/js/main.098f5c9b.js line 1 col 475891 in [anonymous]
File "/nerdybot-v2/api/centipede/jsdom/lib/jsdom/browser/Window.js" line 545 col 19 in Timeout.callback [as _onTimeout]
File "timers.js" line 380 col 14 in ontimeout
File "timers.js" line 244 col 5 in tryOnTimeout
File "timers.js" line 214 col 5 in Timer.listOnTimeout

UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36