Version 2.5.3's marking of read messages is incompatible with non-current Firefox versions about threema-web HOT 3 CLOSED

From another test today, in which I could not reproduce the problem with the most current Firefox ESR (115.X), I came to the conclusion that this more likely a browser-problem!
I am still using a Firefox ESR 92 as my default browser and my friend an even older version. So I changed the topic of this bug report.

from threema-web.

The last release of Firefox ESR 91 is over 1.5 years old. You will be missing a lot of security updates and fixes.

Threema Web supports versions of Firefox currently supported by Mozilla (121, as well as the 115 ESR), in combination with the latest Android app. We strongly recommend using an up to date web browser. Using outdated web browsers poses a big security risk.

The same counts for outdated operating systems that won't get security updates (Windows 7) as well as outdated Android versions that won't get security updates (Android 6).

from threema-web.

I think, we all know the questionable practice of big and fast version-numbering. Only three weeks ago Firefox ESR 91 was the second to last "normal" version of this browser. So I do not consider it thaaat old.
There are people using Firefoxes as old as version 68 (not an example of this bug report) on a daily basis and won't update since the more modern versions won't be usable on their devices. For the same reason I will never get an Android update for my smartphone, because there is none available! (And I still won't throw it when all I want to do is chatting with friends.) --- Even today, you can use PCs and smartphones for more than two years. Just try it!

I accept that it is not practicable to keep applications backwards compatible forever. So I will keep running version 2.5.2 on FF ESR 92.
But it would have been helpful to mention this break in compatibility. (I did not find something within the change log, so I considered this being a bug.)

from threema-web.