Thank you for reply.
You gave me new leads to follow, and it helped.
I already tried to disable firewall in windows 11, and all other stuff i have that *
might* interfere with the installation including my PiHole DNS server... but it didnt change anything.
I did look for errors in eventviewer
before i posted here for help but could not find any logs... like there was NOTHING that mentioned aquasuite-setup.exe or anything in that alley. I didn't think about the total absense of logs until your question about error logs in windows... that made me ReDownload the installer fresh from your website - and Viola! now it works.
The first download must have been damaged in transit or something
Thank you for the help to find the solution

and thank you for an awesome product!
o7 CmdrFlemming