How i can get back the manual change of the text encoding?
According to the current state of the version 93, Linux and the info from this article - https://support.mozilla.org/en-US/kb/text-encoding-no-longer-available-firefox-menu#firefox:linux:fx93 the old function for a manual change of the text encoding was removed.
How can i get it back?
This function is critical for me. It it is completely removed from Firefox, them i will downgrade it or look for another browser that still support it.
Is the problem that the menu item is grayed out, or that when you use the menu item, Firefox does not automatically select the correct encoding?
If the problem is that Firefox chooses the wrong encoding, you can file a bug so the developers can improve this feature. Example bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1731482
But for now, I'm not sure there is a built-in solution for reprocessing the page with a different encoding; I haven't discovered any hidden menu.
On Chrome, there are a couple of extensions that re-request the page and override the charset in the response header so Firefox is triggered to use that encoding instead. I didn't notice a Firefox extension along those lines yet, but perhaps someone can port over one of the Chrome ones if it works correctly.
Can you post a link to a publicly accessible page (i.e. no authentication or signing on required)?