I can run the classic version just fine. I decided to "donate" by purchasing on the MS Store based on your recommendations. I can't run the app because I get that same "The data area passed to a system call is too small" error. I have 32GB of Ram, almost all is free, I reboot cleanly and still can't run the paid version. Additional info: C:\Program Files\WindowsApps\MartinPikryl.WinSCP_126.96.36.199_x86_tvv458r3h9r5m\winscp.exe
Running Win10 Pro, latest updates applied.
Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.