<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 5.17.9

Error message:
Out of memory

Stack trace:
(0041C260) System::DynArraySetLength
(0041C260) System::DynArraySetLength
(0041C391) System::DynArraySetLength
(00400752) System::Sysutils::TEncoding::GetString
(003D0A4A) System::Inifiles::TMemIniFile::LoadValues
(003D06A9) System::Inifiles::TMemIniFile::TMemIniFile
(003D0654) System::Inifiles::TMemIniFile::TMemIniFile
(00C60F7E) TConfiguration::Import
(00E01B93) TLoginDialog::ImportActionExecute
(003A4C5F) System::Classes::TBasicAction::Execute
(003A5954) System::Classes::_18201
(00015307) USER32.dll
(00015D45) USER32.dll
(000167D2) USER32.dll
(00016895) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.