Twenty sixteen theme no register button

Running: Twenty Sixteen Version: 1.2
plugins: Akismet, Broken Link Checker, Dropbox Photo Sideloader, Google Maps Widget, Jetpack by WordPress.com, PayPal Donations, UpdraftPlus – Backup/Restore.
Other: I tried getting wordfence’s firewall installed, but couldn’t due to my PHP5.6 server not having an accessible php.ini file, even through phpmyadmin.

I made a screenshot of what’s basically my problem:
https://www.dropbox.com/s/vjs4dfxoaxptut2/Screenshot_1.png?dl=0
There’s no register button. It should be simply to the left of the “Lost your password?” link, as it is on the login page of victoryatsea.nl.
I’ve compared the wp-login.php files of both sites, and there’s no difference. The register link should be there, but simply isn’t.
I’ve tried disabling all addons, but still no button.
So I think I’ve thus narrowed it down to the theme, because that’s the only difference I can discern between the two websites as far as this page is concerned.
But I can’t find.. basically anything, on this theme, as far as help or support is concerned.

Also.. I don’t know the first thing about coding, so I’m out of my depth as to how to fix this.
Anybody have a clue?

Thanks in advance,

Joris