Quite often, I am unable to use the 2017 wikitext editor to edit pages because the "Show Preview" functionality will not render the article, and instead will only show the text "[object Object]" in place of the article. This seems to follow longer-than-normal load times, as if my request to render the page is timing out.
The "Review Your Changes" functionality works when I have the Wikitext option chosen, but like the above issue, the Visual option does not work, giving me an infinite progress bar.