Thanks for your report.
I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.
Tried drag-drop of files from zip folder opened in WinRAR onto Linux folder opened in WinScp
WinSCP 5.7
Error message:
List index out of bounds (0)
Stack trace:
[014A35F5] System::Classes::TList::Get
[014A35F5] System::Classes::TList::Get
[01559AAA] Customdirview::TCustomDirView::DDProcessDropped
[0157F35B] Dragdrop::TDragDrop::WndMethod
[014C0678] System::Classes::_18201
[76CC62F7] USER32.dll
[76CC6D35] USER32.dll
[76CC77BF] USER32.dll
[76CC7885] USER32.dll.DispatchMessageW