I logged into my Celemony account and downloaded Melodyne Essential 4.1.1.011 (Windows version). It took an age to download. When finally ready, I tried unsuccessfully to unzip the zipped file, either with Windows or 7-Zip. Assuming the file was corrupted, I downloaded it again. The second file was identical in size to the first one. It wouldn't unzip either so I copied it to another computer and unzipped it successfully this time using BitZipper. Seems pointless that they bothered to compress the file, as the zipped version was marginally larger than the original file itself. Anyway, back on the main computer the file would not run. It had no file extension, so I tried adding the extension ".exe", but this did not help either.

Any ideas? What can I try next?

Not sure if Essential is the same, I have Studio, but I was under the impression that the downloads were all the same it just depended on what license you had as to what was installed or something like that. Here is a pic of the contents of my zip for comparison. (did you get a 'personalized' zip, like with your user name in the file name?)
 

Matron Landslide
...Here is a pic of the contents of my zip for comparison. (did you get a 'personalized' zip, like with your user name in the file name?)
 

 
Yes I did, but my zip file only contained one single file with no file extension and with the same name as the zipped file.

On Windows it is a 115MB file with a zip extension. The Mac file is a 87MB with a dmg extension. I just downloaded both and they both opened in 64bit 7-zip 16.04 on Win10 (the current version on 7-zip site). I do have extensions turned on in Windows Explorer and used a download manager to get the file. May be a problem with your browser. I used FireFox 56.0.1.
 
The contents of the zip is similar to the image above: ini files, cabs, setup.exe....
The contents of the dmg is a Melodyne folder containing the files for a Mac.

On a whim I tried renaming the file and adding the file extension ".zip". Then I ran BitZipper on it and it extracted a set of 15 files resembling Matron's screenshot above.

I didn't really expect that to work but it did. A zip of a zip seems pointless and an unidentified filetype makes it confusing. It certainly wasted a lot of time for me. I'll be busy today and won't get time to continue with this until Saturday now.

scook
...May be a problem with your browser. I used FireFox 56.0.1...

 
I was using IE. I have not installed any browsers on my new DAW PC, as I keep it offline except when certain particular installations require internet access. I had assumed that the Melodyne required online installation. Otherwise I would have downloaded it on a different PC.

Celemony supplies the installer with a file extension. What the browser and OS do with the file is another matter. I recall a problem with some of the X Series installers being downloaded without extensions when using IE some years ago.

Finally got it sorted. It installed without any issues and works fine. I hadn't bothered to install Melodyne on my previous o/s installation, as I had not used it much on the setup before that. I like this version (v4) better than the earlier one (v2) and will probably use it more in future. V-Vocal is certainly not redundant though.