Clicking on the “Handicap” dropdown menu greys out all choices except for “none”. All behave as noninteractive elements.
This occurs in Firefox 40.0 for Linux Mint running under Linux Mint 17.1 Cinnamon 64-bit. But not in Chrome 44.0.2403.155 (64-bit) running under Linux Mint 17.1 Cinnamon 64-bit.
I tried deleting all OGS cookies and I cleared the browser cache to no avail.
It’s probably just my browser acting funny, but thought I’d mention it. Chances are it’ll start working again the next time Firefox comes out with an update. 
– Samraku