While I do most of my daily web work using Brave, I keep Vivaldi on hand if I want to perform web searches using Swisscows. Due to an apparent privacy and security restriction, I have not been able to access the Swisscows search engine when I am using Brave as my browser. This morning I did a quick web page lookup using Vivaldi. An hour or so later, I tried to run Vivaldi again from the Applications folder. Only this time, I encountered the familiar but disturbing overlay image on the app icon that indicated that my vintage (10.12) but still usable version of the macOS was not compatible. What to do?
Using Brave, I searched for the web page that would allow me to download and install an older version of Vivaldi. After I found the download page and installed version 5.3, I was again able to use Vivaldi to perform web searches.
Old Versions of Vivaldi
To prevent Vivaldi from automatically upgrading the browser to v.5.4 and higher, I put a lock on the file using the Get Info command.