Invalid access to memory - Vcl::Forms::TMonitor::GetBoundsRect

<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 5.7.6

Error message:
Invalid access to memory.

Stack trace:
(001DCD88) Vcl::Forms::TMonitor::GetBoundsRect
(0005A7EA) ntdll.dll
(0000F15E) ntdll.dll.KiUserExceptionDispatcher
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(000A1411) FatalExceptionMessageDialog
(00083536) ShowExtendedExceptionEx
(0001AB28) TCustomScpExplorerForm::ShowExtendedException
(00077BDD) TTerminalManager::TerminalShowExtendedException
(0070F0E8) TTerminal::ShowExtendedException
(003402A8) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(000167CE) USER32.dll
(00016895) USER32.dll.DispatchMessageW

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.)>
I wasn't even aware this error had happened until I found the "Invalid access to memory" warning window while I was closing other windows on my system. Not sure how long it was there, as my system hasn't been restarted for several days, and many (10+) different application windows were open. I was closing down all those windows because Windows 10 notified me I needed to restart to apply their most recent update. I have travelled with the laptop in sleep mode at least 4 times in the last couple of days, and I don't think I've used WinSCP in the last 4 days (so the error may have been there for quite a while at this point.)
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.9.4

Error message:
Invalid access to memory.

Stack trace:
(0020F3E8) Vcl::Forms::TMonitor::GetBoundsRect
(00081D3F) ntdll.dll
(0006F8EA) ntdll.dll.KiUserExceptionDispatcher
(007E0029) CreateMoreMessageDialog
(000C59CB) CreateMessageDialogEx
(000C6238) CreateMoreMessageDialogEx
(000C640A) MoreMessageDialog
(000C7F10) ExceptionMessageDialog
(000C81D1) FatalExceptionMessageDialog
(00099A3E) ShowExtendedExceptionEx
(0001CDA4) TCustomScpExplorerForm::ShowExtendedException
(0008CF31) TTerminalManager::TerminalShowExtendedException
(00772E0C) TTerminal::ShowExtendedException
(0021319A) Vcl::Forms::TApplication::HandleException
(0037322C) System::Classes::_18201
(0002C2B1) USER32.dll
(0000D885) USER32.dll
(0000D1DF) USER32.dll
(0000CF9B) USER32.dll.DispatchMessageW

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 5.9.4

Error message:
Invalid access to memory.

Stack trace:
(0020F3E8) Vcl::Forms::TMonitor::GetBoundsRect
(000624F6) ntdll.dll
(0000F13E) ntdll.dll.KiUserExceptionDispatcher
(007E0029) CreateMoreMessageDialog
(000C59CB) CreateMessageDialogEx
(000C6238) CreateMoreMessageDialogEx
(000C640A) MoreMessageDialog
(000C7F10) ExceptionMessageDialog
(000C81D1) FatalExceptionMessageDialog
(00099A3E) ShowExtendedExceptionEx
(0001CDA4) TCustomScpExplorerForm::ShowExtendedException
(0008CF31) TTerminalManager::TerminalShowExtendedException
(00772E0C) TTerminal::ShowExtendedException
(0021319A) Vcl::Forms::TApplication::HandleException
(0037322C) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(000167BF) USER32.dll
(00016885) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.