I Need Help Please!!!

I am having a problem with WP and I do not know how to resolve it.  Every time I try to leave a comment on someone’s website it responds with this message:  “Error: Please fill the required fields.”  I do not know what that means.  I do not understand what the “required fields” are.  If anyone understands what this means please let me know so I can resolve this problem.  I will be very grateful for any help anyone can offer me.  Thank you so much, Deborah

UPDATE:  Sadje and Leah responded saying the solution to this problem is to respond through the Reader and we can leave comments that way.  I just tried it and it works!  Thank you Sadje and Leah!