Comments Not Working in Depo Masthead

Hi – Newbie here again with another problem using depo masthead theme on www.ads-software.com: https://catalytica.biz/360salon

I tested comment functionality before I published and it worked fine.

Now that I’ve published, I logged out, went to the blog and left a comment, but when I hit submit, the screen went white and the url in the address bar reads: https://catalytica.biz/360salon/wp-comments-post.php

A friend was able to comment, but I’m concerned that others may have the problem I do and this is a forum where comments are the point ??

Any ideas about what might be happening and how to correct?

Thanks!