This is first time I write and maybe my solution all ready has been mentioned !
mp3tag is missing in my windows 11 24H2 context menu.
Instead I now use windows "sendto" in context menu.
Make a shortcut from Mp3tag.exe in the installation folder and move the link to : C:\Users*******\AppData\Roaming\Microsoft\Windows\SendTo.
Now you can begin.
Highlight all folder(s) or/and file(s) you want into mp3tag.
Rightclick on the highlighted files/folders until you see context menu.
Leftclick on "Send to" and then click on Mp3tag.lnk in "sendto" folder.
This will work in every case.
actually mp3tag is in shellmenu/"windows explorer" but not in shellmenu/"total commander". Today I realized that.
Why do you not just use this real solution?
What would be the advantage using Windows 11 "sendto" in context menu?
I use total commander. I do not like windows expolrer. That is why.
AFAIK the context menu should also work in Total commander
Because I us total commander and mp3tag is invisible in total commander shell menu I so instead I use sendto menu.
I have only writen all this because it might help others in the same situation. It is quite simple to use sendto menu. You cannot send to all programs this way but mp3tag works fine here too. 
According to the Total Commander Forum the above solution should work for TC too:
https://www.ghisler.ch/board/viewtopic.php?p=447688#p447688
I use tc 10.52. Maybe I should update. I will look into it. Thank you
There is a TC release candidate 2, v11.50 available since a few days.
(Your TC version v10.52 was released in october 2022.)
I'm a Total Commander user myself (currently on v11.03) and the shell extension is displayed for me (also for previous versions).
It probably makes a difference and won't work if you're using a 32-bit version of TC on a 64-bit Windows, though.
I remember now that kaspersky scan in shell also is missing so it is a tc thing. But sendto is just a reminder in case of..... missing in shell.
I use OneCommander, as it's so much better than Windows Explorer. Not familiar with Total Commander. Has anyone used both OC and TC, that can compare the two?
tc 11.50 rc2 32/64 bit installed but no sign of mp3 tag in context menu
OK, if I were you, I'd just install TC 64-bit and if it still doesn't show, I'd run the manual registration outlined above.
Maybe the problem after all is windows 11. The reason is that explorer.exe context menu is split in two. The fist context menu I see(when I open it) is a short menu with the "missing" tags. Scrolling down I can open the rest of context menu WITHOUT the "missing" tags. That tells me it is a windows thing - no 2 menu should be the whole menu. Probably something 24H2 has not fixed. There are still several errors i windows 11 24H2.
I guess this the end on this unsolved windows 11 24H2 problem. I do not want to tweak anything trying to change it. I think microsoft will solve it in a later update.
well I am a bit irritated
so I investegated the registry
the old contexthandlers menu should be
HKEY_CLASSES_ROOT*\shellex\ContextMenuHandlers
HKEY_LOCAL_MACHINE\SOFTWARE\Classes*\shellex\ContextMenuHandlers
and mp3tag should be there, it isn´t
now there is 2 context menus : first and second(ContextMenuHandlers)
first context menu is called something else and I didn´t find anything
as far as I now can see : ALL shell apps should be in second menu
the reason is something about : that it is smart to use apps from menu one
but no other filemangers can show anything fra menu one
and this is not smart
I really hope this will be fixed
there are 2 ways :
1 microsoft solves the problem
or
2 the app must point in another way so that it ends up in the context menu folder
in plain language : mp3 tag does not point in the directly same way as other shell apps
Many frustrations with Win11 context menu have been discussed. There have been some suggestions with success.
https://community.mp3tag.de/search?context=topic&context_id=66825&q=Win11%20context%20menu%20order%3Alatest&skip_context=true
Windows 11 24H2 is not classic menu. I do not want the classic menu because menu one the is killed.