Invalid access to memory - TTerminalQueue::ItemGetCPSLimit

<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 5.9.3

Error message:
Invalid access to memory.

Stack trace:
(006C4A18) TTerminalQueue::ItemGetCPSLimit
(000624F6) ntdll.dll
(0000F13E) ntdll.dll.KiUserExceptionDispatcher
(006C720D) TQueueItemProxy::GetCPSLimit

(006C4A18) TTerminalQueue::ItemGetCPSLimit
(000624F6) ntdll.dll
(0000F13E) ntdll.dll.KiUserExceptionDispatcher
(006C720D) TQueueItemProxy::GetCPSLimit

(006C4A18) TTerminalQueue::ItemGetCPSLimit
(000624F6) ntdll.dll
(0000F13E) ntdll.dll.KiUserExceptionDispatcher
(006C720D) TQueueItemProxy::GetCPSLimit

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 5.15.4

Error message:
メモリのアクセス違反

スタック トレース:
(0074BEB4) TTerminalQueue::ItemGetCPSLimit
(00087D6F) ntdll.dll
(00073211) ntdll.dll.KiUserExceptionDispatcher
(0074DE3D) TQueueItemProxy::GetCPSLimit

(0074BEB4) TTerminalQueue::ItemGetCPSLimit
(00087D6F) ntdll.dll
(00073211) ntdll.dll.KiUserExceptionDispatcher
(0074DE3D) TQueueItemProxy::GetCPSLimit

(0074BEB4) TTerminalQueue::ItemGetCPSLimit
(00087D6F) ntdll.dll
(00073211) ntdll.dll.KiUserExceptionDispatcher
(0074DE3D) TQueueItemProxy::GetCPSLimit

The problem happens rarely. I cannot reproduce it.