[TC 11.57] Regression: Global synthetic TAB input causes orphaned modal window deadlock

[LEL]

Summary
When global synthetic keyboard input (especially TAB) is sent within the Windows session, TC 11.57 sometimes creates a separate top-level window (a child process) which behaves like a frozen modal dialog...
...This window: Appears in Task Manager as a child process of TC, with the window title "Total Commander (PRESS ALT+TAB)"
Appears in the Alt+Tab list, but selecting it does absolutely nothing (it cannot be switched to)
Cannot receive focus or input
Cannot be closed
Has no owner (hwnd = 0)

Because of this, TC’s main window becomes completely inaccessible and is hidden behind this orphaned window.
TC must be terminated via Task Manager, or taskkill.

Often, I do not notice this until starting TC again, at which point the new instance shows ‘[2] Total Commander...’, confirming the original instance is still running but blocked behind the orphaned window.


Environment
Total Commander 11.57
Windows 10 Pro x64


How to reproduce
This happens when an external program/script rapidly switches between hidden and visible states while sending global TAB keystrokes using SendInput/SendKeys.
A prime example is a compiled batch script running hidden (e.g., using "Advanced BAT2EXE Pro").


Steps: Start TC 11.57
Run an external script/program in the background that automates window focus and sends global TAB input.
When the external processes loop or restart, a focus vacuum occurs.
TC 11.57 catches this signal on its unowned thread and freezes.
TC disappears from the desktop and leaves the ghost window behind.
TC 11.56 does not react to this input at all and remains fully functional.


TC’s main window cannot receive focus until this "dialog" is closed — but the dialog itself cannot be activated, selected, or closed.


Suspected cause
Likely related to this specific fix introduced in TC 11.57 release candidate 5:
"22.04.26 Fixed: When using the "runas" verb to run as administrator, set the hwnd parameter to 0, otherwise the focus will switch away from Total Commander (32/64)"


Note: The external compiled script itself executes and functions perfectly; only Total Commander is left in a broken, deadlocked state after the focus transition.

[Sir_SiLvA]

could you be more specific, which TC do you use, 32- or 64-Bit?

[LEL]

sorry.. im using 64-Bit

[Dstruct]

Maybe check this:

10.03.26 Added: wincmd.ini [Configuration] AltTabWindow=0 : do not create a hidden window to return to Total Commander via Alt+Tab when minimized to the system tray (32/64)

[zhugecaomao]

I think Dstruct is correct, you can try to set

Code: Select all

AltTabWindow=0 

When minimizing to the system tray of the taskbar, an invisible window is created, which can be used to return to Total Commander by pressing Alt+Tab and Enter

[LEL]

Alt+Tab and Enter does not aktivate TC... but i noticed, clicking the system tray icon does.
But the problem is still... why does TC disappear from the desktop, and why is it impossible to get it back from the ALT+TAB-list?

[zhugecaomao]

If not necessary, untick Configuration - Operation - Move icon to system tray when minimized

TC then will not be “disappear” and ALT+TAB will works as usual

[ghisler(Author)]

Your script seems to somehow signal to Total Commander that it was minimized. Maybe you can find out how you are triggering this by looking at what Total Commander does: When it receives a WM_SIZE message, it calls
popupWindow:=GetLastActivePopup(mainWindowHandle)
to get the currently active modal dialog (or the main handle if none).
Then it calls IsIconic(popupWindow) to check whether the window is minimized.
If yes, and the user has chosen to minimize to tray, Total Commander creates the tray icon and hidden Alt+Tab window and hides its minimized main window.

You write that this is a regression, but compared to what version? This behavior has existed for many years, the only thing changed is that you can now disable the creation of that hidden window with AltTabWindow=0. Then you need to click on the tray icon to restore Total Commander, Alt+Tab (+Enter) will not work.

[LEL]

i have never seen this behavior in any prior version (TC minimizes "itself" doing nothing. just running in the background)... and "AltTabWindow=0" did not stop TC from doing it.
Kinda annoying when TC is gone from the dektop almost every time i intend to use it... and thats alot.
but... maybe there is something else/more that triggers TC to minimize, because since yesterday, it have happend a few times without running my script

[ghisler(Author)]

You need to give me more details if you want to see this fixed. I cannot help you with the little information you provided.
Can you post a sample script which causes this, please?

[ghisler(Author)]

"AltTabWindow=0" did not stop TC from doing it

I have checked the sources: the "Press Alt+Tab..." window title is also used in a different place: For the rubber band selection window which is shown when:
1. You have checked "Left mouse button" and "Rubber band selection" in Configuration - Options - Operation
and
2. You hold down the left mouse button behind a file name and then drag it across multiple files.

Maybe you are triggering this window? Please try unchecking "Rubber band selection" in Configuration - Options - Operation.

[ghisler(Author)]

Since there is nothing I can do to prevent this, I'm moving this thread to the "will not be changed" forum.

Moderator message from: ghisler(Author) » 2026-05-28, 10:00 UTC

Moved to will not be changed

[LEL]

by *zhugecaomao » 2026-05-24, 04:18 UTC
If not necessary, untick Configuration - Operation - Move icon to system tray when minimized
TC then will not be “disappear” and ALT+TAB will works as usual

I think that was the problem. For some reason i hade it ticked in 11.57 but not in older versions (i checked in several backups)
It was probably this setting, together with my script, triggered the problem
So i admit.. it was kind of a user error.
Thanx for the help

[zhugecaomao]

It’s good to see the problem solved

[ghisler(Author)]

It's still strange why they get a deadlock with the Alt+Tab hidden window. Without a sample script I can't really reproduce and fix it...