From Slack:

"In the meantime in order to avoid the annoying SSL error message on your browser you can visit the stats site without SSL at http://zhash.pro"

"MIGRATION UPDATE: Dear friends, the migration is underway and is happening in the background while we are enjoying strong pool rewards the past few days.  It has been a long time coming and we are as excited as you are for the system upgrade!  Upon completion of the work we will inform you on how to update your miners in order to smoothly transfer over to the new system.

WEBSITE MAINTENANCE:  Work on the existing SSL site (https://zhash.pro) is scheduled for today Jan 26 from 8:00pm to 9:00pm GMT+0 (UTC) time.  You may notice that the SSL site may be down at times but do not worry this will NOT affect mining.  The non SSL (http://zhash.pro) site is operating and you can view your stats there.  Please direct your web browser to open the http://zhash.pro site by typing the entire address.  Browsers tend to open the https:// sites by default so you may have to try a few times before the non SSL site opens.

As always, thank you for your support!"