For Curtains you find these system requirements listed on the product page:

Would you think that Windows 11 is above Windows 10? Then you fell into the same trap as I did. The system requirements refer specifically to a higher than 1809 Windows 10 version. No Windows 10 version can ever become Windows 11, because that is - Windows 11, a different animal. Actually a super-correct statement, but very misleading for most. Nobody will in practice exclude Win11 from it. A short message "Not yet compatible with Win11" would have given clarity and many cracks that customer confidence in Stardock will be getting, could have been avoided. More so that Stardock does not seem to belong to the kind of companies that need to create such little misunderstandings to be able to sell at all.
So, this is the surprising news that the Curtains installer will put on your screen, and you start wondering whether you by mistake have downloaded an older version. No. You didn't. Unfortunately.

So, I bought Curtains last week, incautiously skipping the trial while not having detected information that it could not run under Windows 11. Start11 and Fences do (by the way software I wouldn't want to miss anymore for a single day). So, ok, I thought and made peace with it, it's going to be a couple of weeks and then they update it.
Wrong again. According to this table, the installer might be sitting on my hard drive forever without ever getting the privilege to be installed on any of my Win11 machines, as Curtains does not seem to be on the list of Stardock-software that will be made compatible with Win11:
This finding crossed my personal red line and was the actual cause to sit down and write this message.
Although I probably have waived my 14 days money-back guarantee which is usually required to purchase and download a software in Europe: what is your take on a reimbursement in this cases?
Many thanks,
Joerg