Show the issue. Post screenshots of any errors and provide link for us to try your blog.

Hi, could you test whether this is caused by Tracking Protection? Some commenting systems used across a lot of sites are considered trackers, so you may need to make an exception. Here's how:

Load the page, then, at the left end of the address bar, click the shield icon (it's to the left of the lock icon). When the panel drops down, click the slider switch at the top to turn off Tracking Protection.

Any difference?

I am fed up. This is so very, very annoying. Nothing is making any sense. No help! Why is this happening??

So just to summarize: you turned off tracking protection and you still cannot reply to comments on your blog.

What blogging platform do you use?

What happens when you try to reply to a comment - is it that you can't sign in? is it some other problem?

I am on Google platform.

I can post responses on the blogs of others, but I can not respond to posts on my own blog. It is very annoying. A

I wish this problem to be solved as soon as possible...thank you.

BELOW IS COPY OF EMAIL I RECEIVED FROM MOZILLA!!!!!!

If Firefox had fixed my problem when I first asked it to do so days ago, I would not have to keep repeating myself, asking for Firefox to fix the problem!!!

So much for good service! There isn't any!

COPY OF MOZILLA'S EMAIL......

"You have two ongoing support forum threads on this at https://support.mozilla.org/en-US/questions/1480487 and https://support.mozilla.org/en-US/questions/1489974 I know you are getting frustrated but Please stop posting new threads asking the same thing as it does not help you. It makes it harder for people to know what has been suggested or tried already and also people will more likely ignore your if they see you created six threads on the same subject over and over. Also as per https://support.mozilla.org/en-US/kb/mozilla-support-rules-guidelines Posting support requests Create one thread and only one thread for each subject or Mozilla product you need help with."

I am on Google platform. I can post responses on the blogs of others, but I can not respond to posts on my own blog. It is very annoying.

COPY OF MOZILLA'S EMAIL...... "You have two ongoing support forum threads on this at https://support.mozilla.org/en-US/questions/1480487 and https://support.mozilla.org/en-US/questions/1489974

Actually, it would have been really helpful to mention that other thread before. Have you gotten past the frame error message you mentioned in https://support.mozilla.org/en-US/questions/1480487#answer-1696328 --

Firefox Can’t Open This Page To protect your security, accounts.google.com will not allow Firefox to display the page if another site has embedded it. To see this page, you need to open it in a new window.

-- and you can see the blue login button now, or are you still stuck there? What are you seeing currently in the area below the comments of others? For comparison:

Oddly, after clicking that blue button, Firefox asks whether certain cookies can be used cross-site and after I say Yes, the button changes to "Sign in with Blogger":

Clicking that takes me to https://www.blogger.com/onboarding so I stopped there.

Have you tested in Microsoft Edge or Google Chrome?