Invalid access to memory - Pastools::GetMonitorPixelsPerInch

<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:
Invalid access to memory.

Stack trace:
(00409053) Pastools::GetMonitorPixelsPerInch
(0007DAFF) ntdll.dll
(0006B711) ntdll.dll.KiUserExceptionDispatcher
(004533A7) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(0025B025) Vcl::Controls::TWinControl::WndProc
(0025A66C) Vcl::Controls::TWinControl::MainWndProc
(00380370) System::Classes::_18201
(0003AE69) USER32.dll
(00037335) USER32.dll
(00036ED5) USER32.dll
(00039627) USER32.dll
(0006B6CB) ntdll.dll.KiUserCallbackDispatcher
(0047FA7A) Tbx::_16634
(004911F8) Tbxthemes::_16456
(0003AE69) USER32.dll
(00037335) USER32.dll
(00036ED5) USER32.dll
(0002E03E) USER32.dll
(0006B6CB) ntdll.dll.KiUserCallbackDispatcher
(00037FEF) USER32.dll.PeekMessageW
(0021E9CC) Vcl::Forms::TApplication::ProcessMessage
(000E3A5E) Execute
(000024B4) wWinMain
(008BAA91) C4972_0
(00062058) ntdll.dll.RtlValidSecurityDescriptor
(00062025) ntdll.dll.RtlValidSecurityDescriptor

The problem happens rarely. I cannot reproduce it.

I had locked my computer, when I got back I had gotten this error. Windows explorer also needed a restart at this time.

WinSCP 5.13.6

Error message:
Invalid access to memory.

Stack trace:
(00409E3B) Pastools::GetMonitorPixelsPerInch
(0008247F) ntdll.dll
(0006FFFA) ntdll.dll.KiUserExceptionDispatcher
(0045428F) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(0025BDCD) Vcl::Controls::TWinControl::WndProc
(0025B414) Vcl::Controls::TWinControl::MainWndProc
(00381118) System::Classes::_18201
(0002C311) USER32.dll
(0000D8D5) USER32.dll
(0000D50B) USER32.dll
(00017B67) USER32.dll
(0006FFD4) ntdll.dll.KiUserCallbackDispatcher
(0045340B) Tb2dock::TTBCustomDockableWindow::SetBounds
(00450EAA) Tb2dock::TTBDock::ArrangeToolbars
(00450092) Tb2dock::TTBDock::AlignControls
(0025A08A) Vcl::Controls::TWinControl::Realign
(00259F5F) Vcl::Controls::TWinControl::AlignControls
(00213D02) Vcl::Forms::TScrollingWinControl::AlignControls
(0025CD6B) Vcl::Controls::TWinControl::WMSize
(00023DD4) TCustomScpExplorerForm::Dispatch
(0025BDCD) Vcl::Controls::TWinControl::WndProc
(00216294) Vcl::Forms::TCustomForm::WndProc

The problem happens rarely. I cannot reproduce it.

Hi,

It looks like the error happened either when I disconnected my 2nd screen, or when I reconnected it. I tried to reproduce the problem without succeeding.

WinSCP 5.13.8

Error message:
Accès mémoire invalide.

Trace de la pile :
(00409DBF) Pastools::GetMonitorPixelsPerInch
(0007E16F) ntdll.dll
(0006BD81) ntdll.dll.KiUserExceptionDispatcher

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

Error message:
Invalid access to memory.

Stack trace:
(0042E65B) Pastools::GetMonitorPixelsPerInch
(00083FFF) ntdll.dll
(00071931) ntdll.dll.KiUserExceptionDispatcher
(0048A537) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(00278809) Vcl::Controls::TWinControl::WndProc
(00277E50) Vcl::Controls::TWinControl::MainWndProc
(003A346C) System::Classes::_18201
(00045359) USER32.dll
(00036297) USER32.dll
(00035E35) USER32.dll
(000427ED) USER32.dll
(000718EB) ntdll.dll.KiUserCallbackDispatcher
(004B6E9E) Tbx::_16634
(004C8A3C) Tbxthemes::_16457
(00045359) USER32.dll
(00036297) USER32.dll
(00035E35) USER32.dll
(0002D994) USER32.dll
(000718EB) ntdll.dll.KiUserCallbackDispatcher
(0003FDD6) USER32.dll.PeekMessageW
(0023C1B0) Vcl::Forms::TApplication::ProcessMessage
(008B77D5) TSynchronizeDialog::Execute
(008B6E69) DoSynchronizeDialog
(0001A411) TCustomScpExplorerForm::DoSynchronizeDirectories
(0004DD7F) TScpCommanderForm::SynchronizeDirectories
(00046461) TNonVisualDataModule::ExplorerActionsExecute
(003E6E90) System::Actions::TContainedActionList::ExecuteAction
(001C5A79) Vcl::Actnlist::TCustomAction::Execute
(003A346C) System::Classes::_18201
(00045359) USER32.dll
(00036297) USER32.dll
(000353D6) USER32.dll
(000351AB) 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.)>

First and only time this has occurred. Logged in as usual on desktop, then remoted (Windows 10 Remote Desktop) to desktop from laptop over Pulse VPN. No other ill effects to session with ~11 apps and many windows open; only noticed when returning to desktop. Issue with resolution change between desktop 2560x1440 (dual monitor, 125% display) and laptop 1366x768 (100% display)?

<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.15.1

Error message:
Invalid access to memory.

Stack trace:
(0042E65B) Pastools::GetMonitorPixelsPerInch
(00085B2F) ntdll.dll
(00073A61) ntdll.dll.KiUserExceptionDispatcher
(0049E297) Tb2item::TTBView::DrawItem

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 5.15.2

Error message:
Acceso a memoria no válido

Traza de la pila:
(0042ED97) Pastools::GetMonitorPixelsPerInch
(00087C8F) ntdll.dll
(00073131) ntdll.dll.KiUserExceptionDispatcher
(0048AC33) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(00278F45) Vcl::Controls::TWinControl::WndProc
(0027858C) Vcl::Controls::TWinControl::MainWndProc
(003A3BA8) System::Classes::_18201
(000438E9) USER32.dll
(00025137) USER32.dll
(00024CD5) USER32.dll
(0002D6BD) USER32.dll
(000730EB) ntdll.dll.KiUserCallbackDispatcher
(0002B4DB) USER32.dll.PeekMessageW
(0023C8EC) Vcl::Forms::TApplication::ProcessMessage

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 5.15.9

Error message:
Zugriffsverletzung - ungültiger Zugriff auf den Speicher.

Stack trace:
(0042F057) Pastools::GetMonitorPixelsPerInch
(00087D6F) ntdll.dll
(00073211) ntdll.dll.KiUserExceptionDispatcher

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 5.15.2

Error message:
Invalid access to memory.

Stack trace:
(0042ED97) Pastools::GetMonitorPixelsPerInch
(00087D6F) ntdll.dll
(00073211) ntdll.dll.KiUserExceptionDispatcher
(0048AC33) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(00278F45) Vcl::Controls::TWinControl::WndProc
(0027858C) Vcl::Controls::TWinControl::MainWndProc
(003A3BA8) System::Classes::_18201
(00043389) USER32.dll
(00023F87) USER32.dll
(00023B25) USER32.dll
(0002D0DD) USER32.dll
(000731CB) ntdll.dll.KiUserCallbackDispatcher
(00282B7B) Vcl::Controls::TMargins::SetControlBounds
(002766D6) Vcl::Controls::TWinControl::ArrangeControl
(00276A16) Vcl::Controls::_17018
(00276B94) Vcl::Controls::_17020
(00277037) Vcl::Controls::TWinControl::AlignControls
(002771A6) Vcl::Controls::TWinControl::AlignControl
(00277202) Vcl::Controls::TWinControl::Realign
(002770D7) Vcl::Controls::TWinControl::AlignControls
(00230E7A) Vcl::Forms::TScrollingWinControl::AlignControls
(00279EE3) Vcl::Controls::TWinControl::WMSize
(00027352) TCustomScpExplorerForm::Dispatch
(00278F45) Vcl::Controls::TWinControl::WndProc
(0023340C) Vcl::Forms::TCustomForm::WndProc

The problem happens rarely. I cannot reproduce it.

WinSCP is running on my company PC (guest PC). This guest PC is remotely controlled via Citrix by my home PC (Host PC). Whenever I change on the host PC the Citrix session from full screen to window or vice versa, the error occurs. Switching the Citrix session from full screen to window would be for WinSCP as if the size of the monitor had changed (e. g. from 1920 * 1280 to something smaller).

Greetings from Hamburg, Germany. Stay healthy!

Markus

WinSCP 5.15.2

Error message:
Zugriffsverletzung - ungültiger Zugriff auf den Speicher.

Stack trace:
(0042ED97) Pastools::GetMonitorPixelsPerInch
(0008402F) ntdll.dll
(00071931) ntdll.dll.KiUserExceptionDispatcher
(0048AC33) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(00278F45) Vcl::Controls::TWinControl::WndProc
(0027858C) Vcl::Controls::TWinControl::MainWndProc
(003A3BA8) System::Classes::_18201
(000451B9) USER32.dll
(000364D7) USER32.dll
(00036075) USER32.dll
(0004260D) USER32.dll
(000718EB) ntdll.dll.KiUserCallbackDispatcher
(00037A9F) USER32.dll
(000451B9) USER32.dll
(000364D7) USER32.dll
(00035A2A) USER32.dll.CallWindowProcW
(00279056) Vcl::Controls::TWinControl::DefaultHandler
(00278F45) Vcl::Controls::TWinControl::WndProc
(0023340C) Vcl::Forms::TCustomForm::WndProc

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.

Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

<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 5.17.3

Error message:
Virheellinen muistiviittaus.

Pinon jäljitys:
(0042F99F) Pastools::GetMonitorPixelsPerInch
(00087E3F) ntdll.dll
(000732D1) ntdll.dll.KiUserExceptionDispatcher
(0048BC0F) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(00279B7D) Vcl::Controls::TWinControl::WndProc
(002791C4) Vcl::Controls::TWinControl::MainWndProc
(003A47E0) System::Classes::_18201
(000434B9) USER32.dll
(00023FF7) USER32.dll
(00023B95) USER32.dll
(0002D1DD) USER32.dll
(0007328B) ntdll.dll.KiUserCallbackDispatcher
(00028F6B) USER32.dll.PeekMessageW
(0023D524) Vcl::Forms::TApplication::ProcessMessage
(00102522) Execute
(00002658) wWinMain
(00F856F1) C5164_0
(00066C22) ntdll.dll.RtlGetAppContainerNamedObjectPath
(00066BEF) ntdll.dll.RtlGetAppContainerNamedObjectPath

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 5.17.6

Error message:
Invalid access to memory.

Stack trace:
(0042FC8F) Pastools::GetMonitorPixelsPerInch
(0008510F) ntdll.dll
(000725C1) ntdll.dll.KiUserExceptionDispatcher
(0048C06B) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(00279E65) Vcl::Controls::TWinControl::WndProc
(002794AC) Vcl::Controls::TWinControl::MainWndProc
(003A4AC8) System::Classes::_18201
(0003C9D9) USER32.dll
(000336F5) USER32.dll
(000332F5) USER32.dll
(000371ED) USER32.dll
(0007257B) ntdll.dll.KiUserCallbackDispatcher
(00E02CB4) TMessageForm::CMShowingChanged
(00279E65) Vcl::Controls::TWinControl::WndProc
(0023432C) Vcl::Forms::TCustomForm::WndProc
(00E4159C) Vclcommon::C2992_0

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.

Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

<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:
Invalid access to memory.

Stack trace:
(00430B87) Pastools::GetMonitorPixelsPerInch
(000861AF) ntdll.dll
(00072B31) ntdll.dll.KiUserExceptionDispatcher
(004B857C) Tbx::TTBXToolbar::DrawNCArea
(0048CF4B) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(0027ACF1) Vcl::Controls::TWinControl::WndProc
(0027A338) Vcl::Controls::TWinControl::MainWndProc
(003A5954) System::Classes::_18201
(0003DF59) USER32.dll
(00034EC5) USER32.dll
(00034AC5) USER32.dll
(0003868D) USER32.dll
(00072AEB) ntdll.dll.KiUserCallbackDispatcher
(00284927) Vcl::Controls::TMargins::SetControlBounds
(00278482) Vcl::Controls::TWinControl::ArrangeControl
(002787C2) Vcl::Controls::_17018
(00278940) Vcl::Controls::_17020
(00278E07) Vcl::Controls::TWinControl::AlignControls
(00232C26) Vcl::Forms::TScrollingWinControl::AlignControls
(00273938) Vcl::Controls::TControl::RequestAlign
(0027D400) Vcl::Controls::TWinControl::SetBounds

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 5.19

Error message:
Invalid access to memory.

Stack trace:
(00452637) Pastools::GetMonitorPixelsPerInch
(000878AF) ntdll.dll
(00073EE1) ntdll.dll.KiUserExceptionDispatcher
(004AE763) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(002800B5) Vcl::Controls::TWinControl::WndProc
(0027F6FC) Vcl::Controls::TWinControl::MainWndProc
(003C7838) System::Classes::_18201
(0003DEB9) USER32.dll
(00034E75) USER32.dll
(00034A75) USER32.dll
(0003863D) USER32.dll
(00073E9B) ntdll.dll.KiUserCallbackDispatcher
(00032FE3) USER32.dll.GetSystemMetricsForDpi
(0003DEB9) USER32.dll
(00034E75) USER32.dll
(00034552) USER32.dll
(000326F6) USER32.dll.CallWindowProcW
(002801C6) Vcl::Controls::TWinControl::DefaultHandler
(002800B5) Vcl::Controls::TWinControl::WndProc
(0023A57C) Vcl::Forms::TCustomForm::WndProc

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 5.19.2

Error message:
Invalid access to memory.

Stack trace:
(004527D7) Pastools::GetMonitorPixelsPerInch
(0008788F) ntdll.dll
(00073EC1) ntdll.dll.KiUserExceptionDispatcher

The problem happens rarely. I cannot reproduce it.

Error randomly appeared during an SFTP session to CentOS 7.x server.
It is installed on Windows 10 PC. OS information below:
Edition Windows 10 Pro
Version 20H2
Installed on ‎12/‎01/‎2021
OS build 19042.1237
Experience Windows Feature Experience Pack 120.2212.3530.0
Basic Hardware Info is below:
Device name xxxx
Processor AMD Ryzen Threadripper 2950X 16-Core Processor 3.50 GHz
Installed RAM 128 GB (128 GB usable)
Device ID xxxx
Product ID xxxx
System type 64-bit operating system, x64-based processor
Pen and touch Touch support with 256 touch points


WinSCP 5.19.2

Error message:
Invalid access to memory.

Stack trace:
(004527D7) Pastools::GetMonitorPixelsPerInch
(000878AF) ntdll.dll
(00073EE1) ntdll.dll.KiUserExceptionDispatcher
(004C21CF) Tb2item::TTBView::DoUpdatePositions
(004D07A2) Tb2toolbar::TTBToolbarView::DoUpdatePositions
(004C23E0) Tb2item::TTBView::UpdatePositions
(004AD8F2) Tb2dock::TTBCustomDockableWindow::Arrange
(004DB36F) Tbx::_16633
(000285DB) TCustomScpExplorerForm::ThemeChanged
(00280255) Vcl::Controls::TWinControl::WndProc
(0023A71C) Vcl::Forms::TCustomForm::WndProc

The problem happens rarely. I cannot reproduce it.

WinSCP was running when I put my laptop to sleep. When it woke up, this error showed. Never saw it before.

WinSCP 5.19.1

Error message:
Invalid access to memory.

Stack trace:
(004527CB) Pastools::GetMonitorPixelsPerInch
(0008788F) ntdll.dll
(00073EC1) ntdll.dll.KiUserExceptionDispatcher
(004D84FD) Tbx::TTBXItemViewer::Paint
(004C272B) Tb2item::TTBView::DrawItem

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 5.19.6

Error message:
Unzulässiger Zugriff auf einen Speicherbereich.

Stapelverfolgung:
(00452963) Pastools::GetMonitorPixelsPerInch
(00097AFF) ntdll.dll
(00076021) ntdll.dll.KiUserExceptionDispatcher
(004AEA97) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(002803E1) Vcl::Controls::TWinControl::WndProc
(0027FA28) Vcl::Controls::TWinControl::MainWndProc
(003C7B64) System::Classes::_18201
(00046DD0) USER32.dll
(00026275) USER32.dll
(00025D05) USER32.dll
(0002EBED) USER32.dll
(00075FDA) ntdll.dll.KiUserCallbackDispatcher
(0002CB05) USER32.dll.PeekMessageW
(00243D88) Vcl::Forms::TApplication::ProcessMessage
(00108E87) Execute
(00002658) wWinMain
(00FC2C59) C5162_0
(00067E7D) ntdll.dll
(00067E48) ntdll.dll

The problem happens rarely. I cannot reproduce it.

I had WinSCP open on a remote SFTP server. I left it like that for several hours. I was closing applications before shutting down for the date and found WinSCP showing this error dialog.

WinSCP 6.1

Error message:
Invalid access to memory.

Stack trace:
(0046376F) Pastools::GetMonitorPixelsPerInch
(000974CF) ntdll.dll
(00077751) ntdll.dll.KiUserExceptionDispatcher
(004BFF77) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(003F6279) Vcl::Controls::TWinControl::WndProc
(003F58C0) Vcl::Controls::TWinControl::MainWndProc
(00214D34) System::Classes::_18201
(000313A1) USER32.dll
(000220B1) USER32.dll
(00021B35) USER32.dll
(0002BA9D) USER32.dll
(0007770B) ntdll.dll.KiUserCallbackDispatcher
(0002A9B4) USER32.dll.PeekMessageW
(003B9C68) Vcl::Forms::TApplication::ProcessMessage
(00116E76) Execute
(000027EF) wWinMain
(01002C1D) __wstartup
(0006A749) ntdll.dll
(0006A6CA) ntdll.dll

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 6.1.1

Error message:
Invalid access to memory.

Stack trace:
(004637D3) Pastools::GetMonitorPixelsPerInch
(0009783F) ntdll.dll
(000777B1) ntdll.dll.KiUserExceptionDispatcher
(004BFFDB) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(003F62DD) Vcl::Controls::TWinControl::WndProc
(003F5924) Vcl::Controls::TWinControl::MainWndProc
(00214D98) System::Classes::_18201
(000313B1) USER32.dll
(000221B1) USER32.dll
(00021C35) USER32.dll
(0002BB2D) USER32.dll
(0007776B) ntdll.dll.KiUserCallbackDispatcher
(0002AA54) USER32.dll.PeekMessageW
(003B9CCC) Vcl::Forms::TApplication::ProcessMessage
(00116EDA) Execute
(000027EF) wWinMain
(01001521) C5951_0
(0006A799) ntdll.dll
(0006A71A) ntdll.dll

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.

@imani: Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

<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 6.1.2

Error message:
Ошибка доступа к памяти.

Трассировка стека:
(00464087) Pastools::GetMonitorPixelsPerInch
(00087A7F) ntdll.dll
(000740D1) ntdll.dll.KiUserExceptionDispatcher
(004C088F) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(003F6B91) Vcl::Controls::TWinControl::WndProc
(003F61D8) Vcl::Controls::TWinControl::MainWndProc
(0021564C) System::Classes::_18201
(00040209) USER32.dll
(000371C5) USER32.dll
(00036DB5) USER32.dll
(0003A98D) USER32.dll
(0007408B) ntdll.dll.KiUserCallbackDispatcher
(004BFA0B) Tb2dock::TTBCustomDockableWindow::SetBounds
(004BD4A6) Tb2dock::TTBDock::ArrangeToolbars
(004BF76B) Tb2dock::TTBCustomDockableWindow::ChangeSize

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 6.3.3

Error message:
Virheellinen muistiviittaus.

Pinon jäljitys:
(004769D3) Pastools::GetMonitorPixelsPerInch
(0009823F) ntdll.dll
(00077E51) ntdll.dll.KiUserExceptionDispatcher
(004E6F5B) Tb2item::TTBView::DoUpdatePositions
(004F55CE) Tb2toolbar::TTBToolbarView::DoUpdatePositions
(004E716C) Tb2item::TTBView::UpdatePositions
(004D25F2) Tb2dock::TTBCustomDockableWindow::Arrange
(00407752) Vcl::Controls::TWinControl::Realign
(00407627) Vcl::Controls::TWinControl::AlignControls
(003C1412) Vcl::Forms::TScrollingWinControl::AlignControls
(0040A433) Vcl::Controls::TWinControl::WMSize
(0002C987) TCustomScpExplorerForm::Dispatch
(00404951) Vcl::Controls::TControl::WndProc
(00409495) Vcl::Controls::TWinControl::WndProc
(003C39A4) Vcl::Forms::TCustomForm::WndProc

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 6.3.5

Error message:
Accès mémoire invalide.

Trace de la pile :
(004764CF) Pastools::GetMonitorPixelsPerInch
(00098E2F) ntdll.dll
(00078201) ntdll.dll.KiUserExceptionDispatcher
(004D3017) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(00408FE1) Vcl::Controls::TWinControl::WndProc
(00408628) Vcl::Controls::TWinControl::MainWndProc
(00226F2C) System::Classes::_18201
(00032801) USER32.dll
(00023601) USER32.dll
(00023085) USER32.dll
(0002CFED) USER32.dll
(000781BB) ntdll.dll.KiUserCallbackDispatcher
(000201A7) USER32.dll
(000202DB) USER32.dll
(00032801) USER32.dll
(00023601) USER32.dll
(00022F72) USER32.dll.CallWindowProcW
(004090F2) Vcl::Controls::TWinControl::DefaultHandler
(004044C9) Vcl::Controls::TControl::WndProc
(00408FE1) Vcl::Controls::TWinControl::WndProc
(003C35E8) Vcl::Forms::TCustomForm::WndProc

The problem happens rarely. I cannot reproduce it.