After installation of Notepad++ 8.5.2 two entries of "Edit with Notepad++" in context menu are shown with Directory Opus (12.31). Standard File Explorer is fine and only shows one entry.
Notepad++ seems to have a bit of trouble with the context menu as of late (according to the changelog), so unsure which software is at fault.
If anyone is interested, the issue is now mentioned at the Notepad++ GitHub.
Total Commander seems to be affected as well.
It’s often because something adds both the new Win11 style context menu item and the separate item for older OS.
All part of Microsoft’s brilliant design for changing context menus in Windows 11 that everyone loves and doesn’t immediately turn off. 
According to Notepad++, Directory Opus is at fault:
Is there maybe a way to manually "delete" one entry in the context menu?
Double-click Preferences / Miscellaneous / Advanced [Troubleshooting]: ignore_context_menus and add NotepadPlusPlus_* to it to remove the duplicate menu item.
We'll block the duplicate shell extension by default in the next update.
From the release notes of Notepad++ version 8.5.2:
Enhance “Edit with Notepad++” context menu and fix several issues. (Fix #13399, #13410, #13425, #13438, #13440, #13446, #13457)
So I would guess that the following 2 commands (in order) should bring things back to normal:
regsvr32.exe /u "c:\path to\NppShell.dll"
regsvr32.exe "c:\path to\NppShell.dll"
This would remove the context menu entries and reinstall them.
(I wrote my own Notepad++ context menu entries, but a quick test with 8.5.2 installs just 1 extra "Edit with Notepad++" entry. Which is how it should be).
There's a newer NP++ 8.5.2 test version linked in the Github thread which has the issue, but blocking the 2nd shell extension fixes things.
Thank you for the fast solution!
Sorry, but after these recent Notepad++ changes (and DO ones?) that context menu entry is gone forever. I do not see it in DOpus any more. Tried reinstalling npp. The entry is there in Explorer.
(Windows 10, npp 8.5.3)
There haven't been any (released) changes on our side yet, so whatever happened is due to Notepad++ changes, i think.
Installing NPP 8.5.3 in combination with NotNull's suggestion fixed the context menu for me.
After just installing the update nothing had changed. Reboot didn't help.
So I re-registered the DLL, then restarted Explorer and Opus. Success.
regsvr32.exe /u "C:\Program Files\Notepad++\contextMenu\NppShell.dll"
regsvr32.exe "C:\Program Files\Notepad++\contextMenu\NppShell.dll"
With NPP installed with default settings or via Winget these commands should work for most people.
Running just the first command and then installing the NPP update should work as well.
Just noticed this the other day and spent some time trying to fix it via the registry and then uninstall/reinstall but without success. This solution did the trick! I should have checked here earlier!!!