Got a crash that erased my hard disk before backup. How can I restore a muse file from the latest version uploaded on Adobe Catalyst server ?
Unfortunately this is not possible. You can only do all over again.
Check this link Is It Possible To Recover A Lost Muse Project File? and see if you can get any help in importing the HTML version of your file.
However again as Pavel Homeriki mentioned you cannot Muse for editing those file, instead you can use any other code editor like Dreamweaver for that purpose.