Is Zoho compatible with windows 10 and firefox 46.0.1?

Is Zoho compatible with windows 10 and firefox 46.0.1?

I have been  developing website software in zoho which worked on everything. Then upgraded it to windows 10 - explorer works but when on fire fox (46.0.1)when I sign on to the web site. no response. What can I do? Is there a compatibility issue?
What should I do? My client is really upset.

Thanks,
Regards,
Geeta