Many Blogger features are vulnerable to security filters. The ability to use Blogger commenting, the EU cookie advice banner won't display or won't go away, the infamous Reading List, the Blogger Stats "Don't track ..." option - all require cookies and scripts, that are subject to filtering.
Any filters, on any given computer, can change, at a moments notice - and without intentional action by the owner of the computer. One common complaint by many computer owners starts out
I didn't change a thing! Commenting / the cookie advice banner / my Reading List / my Stats display just stopped working!In many cases, the owner will be absolutely correct - he did not cause the problem - but he will still have problems with Comments / The Cookie Advice Banner / Post/Page/Template Preview / Reading List / Stats / Template Designer / whatever.
Filters can cause problems, because of various issues which the computer owner cannot control - but which he / she will see.
- Geolocation fuzziness can affect country code alias redirection.
- Newly added country code aliases, by Blogger, can affect country code alias redirection.
- Carrying a portable computer, from country to country, can affect country code alias redirection.
- Ongoing filter updates, by the publisher, can affect any filter, at any time.
The typical computer owner can neither anticipate nor diagnose any of these changes - but they can observe indirect results.
Geolocation fuzziness can be a problem because of country code alias redirection, and apparent changes in computer location.
A computer located somewhere near an international boundary can appear, because of geolocation variation, to be located on either side of a country border. If either country is subject to country code alias redirection, the resulting URL change will affect any filters that are domain based.
An on again, off again filter problem, with only one country subject to alias redirection, will be caused by apparent movement of the computer between countries.
Newly added country code aliases, installed by Blogger, can be a problem because of redirections, which were previously not existent. Computers located in a country which is newly subject to alias redirection will have unanticipated problems with domain based filters, from URLs reflecting the new country code.
Carrying a portable computer, across / near international boundaries, can contribute to either alias redirection issue. The computer owner will be aware of the location change - and may suspect that some problems may be caused by the location changes - but will be unlikely to understand how the problems might be avoided.
Ongoing filter updates, made by the publisher, can be a problem because of changes that will be completely unexpected. This problem will affect every computer in the world, periodically. The changes, made by the various security product publishers, will not be known or understood by the computer owners - and they will happen automatically, without the knowledge of the computer owner.
Many computer owners are not even aware of the presence of security products on a given computer - so subtly are the security products provided, these days.
Ad Blockers, Anti Malware / Anti Spam Protection, Performance Optimisers, and various Security Suites (such as whatever Microsoft is packaging, at any time) - all of these products contain filters. And Blogger / Google, because of their necessary use of multiple domains, provides features that are vulnerable to the filters.
With any of these problems, the simplest diagnosis starts with checking / correcting browser cookie filters - and continues with checking / correcting browser script filters.