Right Click .MHT File in "Windows Explorer" cannot "Open with..." Vivaldi
At least Vivaldi does not show up in the list of supported applications.
Vivaldi will open the .MHT via "File/File Open".
@dskfjl3jlrjl: You probably need to associate the browser with .mht at Control Panel\All Control Panel Items\Default Programs\Set Associations.
@Ayespy You are correct, I could do that manually...
BUT it is still a bug. The Installer/Vivaldi registers itself als handler for .HTM, but MISSES OUT on .MHT while BOTH are relevant file types for the browser.
@dskfjl3jlrjl No, it is not a bug as the Vivaldi installer never set a MIME type association to Vivaldi.
You can do it by hand.
As i know other non MS browsers do not register themselves to MHT files, too.