I must have failed to get the memo about this, but I managed to solve the problem after a bit of sleuthing. I intended to write about this last month when it happened, but my good intention fell through the cracks of my busy life.
In case you are suffering a problem with the Comment function on Blogger, I'll talk about it today.
A curious situation developed a month ago when anyone who tried to comment would see the Verification Code to type but the box in which to insert it was gone. I discovered that both of the recent Firefox and IE updates have new security features to protect your privacy. Unfortunately, they also protect you from anyone placing a comment on your blog if you have a particular Comment setting selected.
Blogger's Comments Settings
You can choose one of three for Comment Form Placement:
Embedded below post
The embedded comment form can not be used if you have Post Pages disabled.
I have always used Embedded below post. Apparently that doesn't work with the updated browser versions.
Change setting to Pop-up window which works fine. I didn't try Full Page, but it probably works also.
Why can't software updates list the critical problems one might incur because of new security features?