Very-very frequent "Assertion failed: FALSE // focus.c, line 1204", during "zz_universal_viewer_5.7.2.0 : 2.GoToPage", on Test KVM AHK, since c7eb46d

Running Wine Test, Module: zz_universal_viewer_5.7.2.0, Test: 2.GoToPage

...

(win32ss/user/ntuser/vis.c:50) err: ATM the Current Window or Parent is dead! BC692F90

(win32ss/user/ntuser/focus.c:1204) err: ASSERT: obj 0xBC692F90, refs 0

*** Assertion failed: FALSE

***   Source File: /srv/buildbot/Test_KVM_AHK/build/win32ss/user/ntuser/focus.c, line 1204

Break repeatedly, break Once, Ignore, terminate Process or terminate Thread (boipt)? 

kdb:>

 o

Execute '.cxr F6D1D280' to dump context

Entered debugger on embedded INT3 at 0x0008:0x80950d0e.

kdb:>

 bt

Eip:

<ntoskrnl.exe:150d0f (:0 (DbgBreakPoint))>

Frames:

<win32k.sys:3d9c5 (win32ss/user/ntuser/focus.c:1204 (co_UserSetFocus))>

<win32k.sys:86646 (win32ss/user/ntuser/winpos.c:2626 (co_WinPosShowWindow))>

<win32k.sys:7dd0b (win32ss/user/ntuser/window.c:2677 (co_UserDestroyWindow))>

<win32k.sys:7f705 (win32ss/user/ntuser/window.c:2833 (NtUserDestroyWindow))>

<ntoskrnl.exe:13535e (ntoskrnl/include/internal/i386/ke.h:712 (KiSystemServiceHandler))>

<ntoskrnl.exe:3da9 (:0 (KiFastCallEntry))>

<ntdll.dll:eda5>

<SumatraPDF.exe:b0ea4>

<user32.dll:62a49>

<user32.dll:56a4b>

<user32.dll:58864>

<ntdll.dll:ecf8>

<user32.dll:578c7>

<SumatraPDF.exe:b1502>

<SumatraPDF.exe:113360>

<00000000>

kdb:>

[SYSREG] Stage took: 1882.360203 seconds

[SYSREG] Rebooting machine (retry 1)