When clicking on the MerlinXL.vsto link on the MerlinXL install page an error appears warning that:
There was an error during installation
Downloading file:///………..MerlinXL.dll.manifest did not succeed
1. You tried to install from a browser other than Internet Explorer/Edge (Microsoft !)
2. You saved the link to your pc first rather than clicking on the link in the webpage to install.
You mustn’t download the install file first. The “Click-Once” installation process installs other files from the same server location. If the .vsto is downloaded first the installation process does not know where to get the other files from.
Click on the .vsto link in Internet Explorer