NB: after i clicked OK on the invalid mem access message, winscp was still running great. no crash , no issues- just the message.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>:
Was just running in the background, overnight. The PC was locked so the monitors were auto turned off. (NOT sleep, nor any kind of hibernation, i have all of that disabled as i run my pc 24/7. I only have the OS set to turn off the monitors after ~60min. However last night i did press WIN+L (which i commonly do when done for the night,so that win11 locks/lockscreen and then clicks off the monitors after ~5min , instead of it auto waiting the ~60min.

IMPORTANT: i did have 2x or 3x .php documents opened/being auto-edited /Live-edited via WinSCP -> Notepad++ (v8.4.4 32bit)- (in all the issues ive had with winscp 5.2.1 and 6.0 auto-editing/Live-editing has been in use). I have server level equpipment, no anti-virus / win-defender disabled (incl. smart-screen). I do run MSERT manually every 2 months or so.
+Supermicro h11 board,
+1x amd epyc cpu
+128g ECC D4 ram (from the supermicro QVL)
+2x nvidia rtx4000 gpus

thanks!
(cant wait for v6.0 to be released, have donated a few time- LOVE WINSCP!!)

<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 6.0

Error message:
Invalid access to memory.

Stack trace:
(002C18B3)
(00097F5F) ntdll.dll
(00076171) ntdll.dll.KiUserExceptionDispatcher
(0047F2C8)
(00491D6E)
(0047EF59)
(00266ADF)
(003D78F8)
(00046D50) USER32.dll
(00026115) USER32.dll
(00024A43) USER32.dll
(0002457B) USER32.dll.DispatchMessageW

Status: unknown_rel_addr

The problem happens rarely. I cannot reproduce it.