<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 5.15.9

Error message:
Error reading RemoteDriveView.Indent: External exception C000001D

Stack trace:
(00735CCE) THierarchicalStorage::ClearValues
(00087D6F) ntdll.dll
(00073211) ntdll.dll.KiUserExceptionDispatcher
(0022130F) Vcl::Graphics::TBitmap::CopyImage
(00222F2C) Vcl::Graphics::TBitmap::SetTransparentColor
(004DEE0F) Pngimagelist::TPngImageList::AddMasked
(0044253D) Customdirview::_16486
(00442634) Customdirview::OverlayImageList

(00735CCE) THierarchicalStorage::ClearValues

(00394BFF) System::Classes::_17687
(00394E39) System::Classes::TReader::ReadProperty
(0039462D) System::Classes::TReader::ReadDataInner
(0039460F) System::Classes::TReader::ReadData
(003A2289) System::Classes::TComponent::ReadState
(00394487) System::Classes::TReader::ReadComponent
(003946A1) System::Classes::TReader::ReadDataInner
(0039460F) System::Classes::TReader::ReadData
(003A2289) System::Classes::TComponent::ReadState
(00394487) System::Classes::TReader::ReadComponent
(003946A1) System::Classes::TReader::ReadDataInner
(003945E0) System::Classes::TReader::ReadData
(003A2289) System::Classes::TComponent::ReadState
(002326BD) Vcl::Forms::TCustomForm::ReadState
(003955BB) System::Classes::TReader::ReadRootComponent
(0038F486) System::Classes::TStream::ReadComponent
(00384ECB) System::Classes::_17089
(0038681F) System::Classes::_17116
(003867F4) System::Classes::_17116
(003868AD) System::Classes::InitInheritedComponent
(00231EB6) Vcl::Forms::TCustomForm::TCustomForm
(00004496) Vcl::Forms::TForm::TForm
(00003B19) TCustomScpExplorerForm::TCustomScpExplorerForm
(0004B152) TScpCommanderForm::TScpCommanderForm
(0023CE66) Vcl::Forms::TApplication::CreateForm
(008CA9E3) _SafeFormCreate
(00002664) wWinMain
(00926161) C5025_0
(00066B72) ntdll.dll.RtlGetAppContainerNamedObjectPath
(00066B3F) ntdll.dll.RtlGetAppContainerNamedObjectPath

The problem happens rarely. I cannot reproduce it.