<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 5.13.3

Error message:
External exception EEFFACE

Stack trace:
(0000B54F) KERNELBASE.dll.RaiseException
(0006248E) ntdll.dll
(0000F15E) ntdll.dll.KiUserExceptionDispatcher
(004D6188) Jclhookexcept::_16408
(008BD2AE) C5104_0
(008BE69F) _ReThrowException
(00023FE2) TCustomScpExplorerForm::GetSpaceAvailable
(0080877B) TFileSystemInfoDialog::CheckSpaceAvailable
(008087E9) TFileSystemInfoDialog::NeedSpaceAvailable
(0025B025) Vcl::Controls::TWinControl::WndProc
(0025611C) Vcl::Controls::TControl::Perform
(0025B18B) Vcl::Controls::_17076
(0025B025) Vcl::Controls::TWinControl::WndProc
(002154EC) Vcl::Forms::TCustomForm::WndProc

The problem happens rarely. I cannot reproduce it.