@kitchin: Thanks for your feedback.

The revised program you sent me works perfectly. Thank you so much.

I have added this bug to the tracker:
Issue 2254 – Failure when trying to upload file using double-click over disconnected session

OK, I sent you a large trace file by email. New email address. Thank you.

@kitchin: 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.

(File names munged in this report - if you need them, tell me.)
Level: Not serious, but not ideal.
Steps to reproduce: Let a session go stale, for instance, by stepping away from the computer for an hour. The screen shows "Reconnect Session" on the right-hand panel. Double-click on a file in the left-hand panel to upload it.
Result: Error.
Expected result: Reconnect and upload file, or just a warning instead of an error.

WinSCP 6.2.2

Error message:
Cannot create remote file '/home/.../class_..._posts_cleanup_sc_util.php'.

Invalid access to memory.

Stack trace:
(00BC5B8A)
(00E1EB06)
(00E20B6E)
(00E1D928)
(0009812F) ntdll.dll
(00077D31) ntdll.dll.KiUserExceptionDispatcher
(00BC410B)
(00C1DA40)
(00C20879)
(00C46BCF)
(00C46DE0)
(00C5F19D)
(00C42C57)
(00C7A283)
(00C78900)
(00C7872D)
(00C4109A)
(00C7818C)
(00011F33)
(00012B54)
(00012DD0)
(0001E447)
(0005C272)
(0048D049)
(0048A9B6)
(0048B5F5)
(00407B29)
(0044AE03)
(00225850)
(00031E51) USER32.dll
(00022C21) USER32.dll
(00022592) USER32.dll.CallWindowProcW
(0007F334) COMCTL32.DLL
(0007F3D3) COMCTL32.DLL
(0007F14C) COMCTL32.DLL
(00031E51) USER32.dll
(00022C21) USER32.dll
(00022592) USER32.dll.CallWindowProcW
(004C1947)
(00225850)
(00031E51) USER32.dll
(00022C21) USER32.dll
(000214E0) USER32.dll
(0002102B) USER32.dll.DispatchMessageW

(00E1F171)
(00E2074B)
(00C477F7)
(00C5F19D)
(00C42C57)
(00C7A283)
(00C78900)
(00C7872D)
(00C4109A)
(00C7818C)
(00011F33)
(00012B54)
(00012DD0)
(0001E447)
(0005C272)
(0048D049)
(0048A9B6)
(0048B5F5)
(00407B29)
(0044AE03)
(00225850)
(00031E51) USER32.dll
(00022C21) USER32.dll
(00022592) USER32.dll.CallWindowProcW
(0007F334) COMCTL32.DLL
(0007F3D3) COMCTL32.DLL
(0007F14C) COMCTL32.DLL
(00031E51) USER32.dll
(00022C21) USER32.dll
(00022592) USER32.dll.CallWindowProcW
(004C1947)
(00225850)
(00031E51) USER32.dll
(00022C21) USER32.dll
(000214E0) USER32.dll
(0002102B) USER32.dll.DispatchMessageW

Status: unknown_rel_addr

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.