Is Counterwallet https://wallet.counterwallet.io working for anyone else with Safari 10.0 / macOS Sierra?

I cannot login at all.

There were times when I needed to use Google Chrome with Counterwallet but have since uninstalled it and would rather not reinstall it for one web site.

The Clearwallet/VIA fork works in Safari fine for me.  Safari 10 is a fairly modern browser, am I really stuck here?