I posted a comment, but now I can't delete it. It's labeled as "Anonymous" - even though I used my Google account!and
I tried to publish my comment, but the Publish button doesn't do anything.Both complaints were representative of the many different problem reports seen.
This problem, in general, starts with the need for authentication by the blog guest or owner, when trying to publish a comment.
You authenticate yourself using the Blogger / Google login wizard. When you authenticate, you create a login cookie, which is later used to identify you when you comment, when you Follow a blog (or maintain the Followers on your blog), and when you maintain or publish to your own blog. The login cookie is now created under "google.com".
Cookies, an essential ingredient in our use of Blogger, have had a controversial past in the Internet, for a long time. Some people believe that filtering cookies, placed on our computers by untrustworthy websites, will allow us to safely visit those websites. Cookie filter settings are part of native browser option wizards, and menus in various browser add-on accessories.
Most cookie activity, in general, involves cookies created and read by scripts running within the same domain. Cookies designed to be created by scripts running from one domain, and read by scripts running from a second domain, are called third party cookies. Many people believe that third party cookies are more dangerous than normal ("first party") cookies. Some cookie filters contain specific settings to block third party cookies, even if normal cookies are permitted.
The complex domain infrastructure used by Blogger / Google necessitates the use of third party cookies. In the case of commenting, this need is caused by use of the Embedded comment form, which runs in the published domain of the blog - not "blogger.com". People who do not permit third party cookie access will have problems with using the embedded comment form.
Until 2011, the various scripts used by the embedded comment form, in situations which required non permitted third party cookie access, provided no feedback to the hapless blog guest or owner. A person trying to comment, on a blog which permitted anonymous commenting, would generate an anonymous comment (even though intentionally selecting Google authentication).
In cases where a blog did not permit anonymous comments, the comment script would simply terminate, leaving no clue.
In 2011, the embedded commenting form scripts were changed. In cases where authentication is required - either with a blog that does not permit anonymous comments, or when the commenter has selected Google authentication intentionally - the guest is now presented with a login screen, and required to authenticate.
If third party cookie access is not permitted, after authentication is completed, the script treats that as if authentication was not provided, and repeats the demand for authentication. This results in a login loop, with the "Remember me" option selected.
In 2014, the Google "One account" login made the problem more universal. Now, all Blogger login cookies are created under "google.com".
Also, we have the effects of country code aliasing, and of custom domain publishing, which creates even more domain URLs, subject to filters - and more opportunities for problems with third party cookies.
With "Remember me" not selected, third party cookie access not permitted, and anonymous commenting allowed, a comment is simply treated as anonymously posted. If anonymous commenting is not desired, or not permitted, the blog guest is again required to authenticate.
In many cases, for blog owners reporting volumes of complaints from blog guests, we have simply recommended changing the comment form style, to use a full page form. Not all blog owners have appreciated this advice.
The only real solution here, which will provide any long term consistency, is for all Blogger blog guests and owners to permit third party cookie access. Unfortunately, not all blog guests and owners are willing (or able) to do this, immediately.
With layered security, varying levels of technical proficiency, and many different security programs and settings, finding a problematic filter setting is going to be frustrating for many. This is, nonetheless, a necessary solution.
Once again, we have a detail, similar to the current problem with the Follower gadget and script filtering, that really is the responsibility of each computer owner.