The error message I had from my original message disappeared when the tag was correctly filled.
I already use "File Type Associations", with the .htm, and many other file extensions for Google Chrome. Adding "<fileExts>" and ".htm" doesn't duplicate what I did ? And what does that change since "HTTP" and HTTPS "is already written ?
My goal is to reduce the "Default Applications.xml" file as much as possible in order to use "File Type Associations" as much as possible.
Like other interlocutors, I would have preferred everything to be in the same interface.