@patrick: Please, pet us know, if the problem ever comes back.

@patrick: all good after a reboot of windows 11 ...
though it's still weird! Maybe interesting to investigate even if not reproductible.
Thank you

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 6.3.6

Error message:
Invalid access to memory.

Stack trace:
(00BDB1EC) TSessionData::IsSame
(00E24D56) C6612_3
(00E26DBE) ____ExceptionHandler
(00E23B78) __ExceptionHandler
(00098F2F) ntdll.dll
(000781B1) ntdll.dll.KiUserExceptionDispatcher
(00C0C81B) TStoredSessionList::UpdateStaticUsage
(00B119C2) TConfiguration::UpdateStaticUsage
(00086B3D) TGUIConfiguration::UpdateStaticUsage
(000F84CA) TWinConfiguration::UpdateStaticUsage
(001165C1) UpdateStaticUsage
(00119236) Execute
(000031E3) wWinMain
(00E22AB9) __wstartup
(0006B0C9) ntdll.dll
(0006B04A) ntdll.dll

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.9.1

Error message:
Zugriffsverletzung - ungültiger Zugriff auf den Speicher.

Stack trace:
(0070595C) TSessionData::IsSame
(00862736) C5073_3
(0086479E) ____ExceptionHandler
(00861558) __ExceptionHandler
(00081D3F) ntdll.dll
(0006F8EA) ntdll.dll.KiUserExceptionDispatcher
(00723F01) TStoredSessionList::UpdateStaticUsage
(00672175) TConfiguration::UpdateStaticUsage
(00068D71) TGUIConfiguration::UpdateStaticUsage
(000B52A6) TWinConfiguration::UpdateStaticUsage
(000D29EB) UpdateStaticUsage
(000D55AF) Execute
(000024A8) wWinMain
(0086076D) __wstartup
(0005FFD7) ntdll.dll
(0005FF9F) ntdll.dll

The problem happens rarely. I cannot reproduce it.