Invalid access to memory - Vcl::Graphics::TCustomCanvas::Lock

<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 5.7.5

Error message:
Invalid access to memory.

Stack trace:
(0004D6DF) ntdll.dll
(00062496) ntdll.dll
(0000F13E) ntdll.dll.KiUserExceptionDispatcher
(0004D5E9) ntdll.dll.LdrFindResource_U
(001BE746) Vcl::Graphics::TCustomCanvas::Lock
(001C3CE5) Vcl::Graphics::FreeMemoryContexts
(0021B955) Vcl::Controls::TWinControl::MainWndProc
(0034021C) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(00015DE8) USER32.dll
(00015E49) USER32.dll
(0000F117) ntdll.dll.KiUserCallbackDispatcher
(0001F75C) USER32.dll
(001E057C) Vcl::Forms::TApplication::ProcessMessage

The problem happens rarely. I cannot reproduce it.

<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 5.7.7

Error message:
Invalid access to memory.

Stack trace:
(0004D6DF) ntdll.dll
(00062496) ntdll.dll
(0000F13E) ntdll.dll.KiUserExceptionDispatcher
(0004D5E9) ntdll.dll.LdrFindResource_U
(001BEA56) Vcl::Graphics::TCustomCanvas::Lock
(001C3FF5) Vcl::Graphics::FreeMemoryContexts
(0021BC65) Vcl::Controls::TWinControl::MainWndProc
(0034059C) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(00015DE8) USER32.dll
(00015E49) USER32.dll
(0000F117) ntdll.dll.KiUserCallbackDispatcher
(0001F75C) USER32.dll
(001E088C) Vcl::Forms::TApplication::ProcessMessage

The problem happens rarely. I cannot reproduce it.

Seems to happen when computer is turned into sleeping mode and then restored in a different environment.

WinSCP 5.7.7

Error message:
Invalid access to memory.

Stack trace:
(0004D6DF) ntdll.dll
(00062496) ntdll.dll
(0000F13E) ntdll.dll.KiUserExceptionDispatcher
(0004D5E9) ntdll.dll.LdrFindResource_U
(001BEA56) Vcl::Graphics::TCustomCanvas::Lock
(001C3FF5) Vcl::Graphics::FreeMemoryContexts
(0021BC65) Vcl::Controls::TWinControl::MainWndProc
(0034059C) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(00015DE8) USER32.dll
(00015E49) USER32.dll
(0000F117) ntdll.dll.KiUserCallbackDispatcher
(0001F75C) USER32.dll
(001E088C) Vcl::Forms::TApplication::ProcessMessage

The problem happens rarely. I cannot reproduce it.