Believe it or not, my registration credentials got accepted by Paddle, and I'm now running my registered copy of Scrivener via WINE 4.0 under LinuxMint.
Thank you Devinganger for your pointer. As you recommended, I installed .NET, and that proved to be the answer.
For those who, like me, are Linux novices but are willing to spend some time on this, here is what I did.
- I went to Software Manager and installed Winetricks
- I ignored the messages about 32-bit and 64-bit prefixes (did not understand them; I've got a 64-bit system)
- In Winetricks, I selected the default wineprefix (without understanding what it meant)
- I clicked Select a Windows dll or component
- I scrolled down to find dotnet 4.6.1
- and selected Install
- What follows is a lengthy procedure - say, one hour - where successive versions of .NET are installed, with worrying popups which you can ignore and click OK on, and where for long stretches of time, nothing seems to be happening (apart from the frantically blinking harddisk LED)
- Whenever an "accept this end user agreement" window pops up, click 'have read and accept'. This occurs for every successive version of .NET. It is apparently a cumulative process, ending with the installation of the .NET version (4.6.1) that I selected.
- When that final version has been installed at last, and no more popups are forthcoming, close all apps or whatever they are called in Linux parlance, and restart your computer.
- Fire up Scrivener, fill in your registration data, wait for that slooow connection to check everything, and hopefully, receive a message like the one I got.