htmlfile registry key deleted incorrectly

My default web browser is Firefox. I recently uninstalled Internet Explorer 11. Subsequently, registry cleaner decided to delete the key:

Open with Application Issue "C:\Program Files\Internet Explorer\IEXPLORE.EXE" -nohome HKCR\htmlfile\shell\open

After doing this, html files could not be opened. I restored this key and html files now open in Firefox.

It seems reasonable to delete this key, since it points to a non-existent file. However, it seems that Windows automatically redirects a request to open an html file to the default web browser.

CCleaner should not delete this key.

I am running CCleaner 5.77.8448 in Windows 10 1909.

Removing a registered web browser always has some caveats, and that's one of them. Even removing a 3rd party browser can end up with broken extensions like HTML if it was registered as the system default web browser. Often it can be fixed by having another browser register as the system default, but it doesn't always work.

It's the sole reason I only use the portable version of 3rd party web browsers since I don't feel like correcting broken file extensions.