Random "Assertion failed: ObjHead->cLockObj < 0x10000" in UserReferenceObject(), at end of "Wine Test > zz_ultravnc_1.0.9.6.2 > 2.view_vnc" on AHK testbot

Running Wine Test, Module: zz_ultravnc_1.0.9.6.2, Test: 2.view_vnc

...

OK: 2.view_vnc: VNC Viewer works as expected.

(win32ss/user/ntuser/winpos.c:3327) err: NtUserSetWindowPos bad window handle!

2.view_vnc: Test failed: 'vncviewer.exe' process failed to close despite 'QEMU (rose-dummy)' window closed. Active Wnd: 'TeamViewer 7 Setup'.

(win32ss/user/ntuser/msgqueue.c:846) err: Remove Window Messages E171C750 From Sent Queue

(win32ss/user/ntuser/msgqueue.c:846) err: Remove Window Messages E170DF40 From Sent Queue

Info: 2.view_vnc: TestsFailed(): Uploading of the screenshot took too long. Terminating.

(win32ss/user/ntuser/msgqueue.c:1277) err: NB Receiving Thread woken up dead!

*** Assertion failed: ObjHead->cLockObj < 0x10000

***   Source File: /srv/buildbot/Test_KVM_AHK/build/win32ss/user/ntuser/object.c, line 700

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

kdb:>

 o

Execute '.cxr F6CA0804' to dump context

Entered debugger on embedded INT3 at 0x0008:0x8094bfbe.

kdb:>

 bt

Eip:

<NTOSKRNL.EXE:14bfbf (:0 (DbgBreakPoint))>

Frames:

<win32k.sys:8a703 (win32ss/user/ntuser/object.c:700 (UserReferenceObject))>

<win32k.sys:77c88 (win32ss/user/ntuser/object.h:33 (co_VIS_WindowLayoutChanged))>

<win32k.sys:83adb (win32ss/user/ntuser/winpos.c:2054 (co_WinPosSetWindowPos))>

<win32k.sys:869a6 (win32ss/user/ntuser/winpos.c:3361 (NtUserSetWindowPos))>

<win32k.sys:86a6f (win32ss/user/ntuser/winpos.c:3278 (NtUserMoveWindow))>

<NTOSKRNL.EXE:13066e (ntoskrnl/include/internal/i386/ke.h:712 (KiSystemServiceHandler))>

<NTOSKRNL.EXE:3da9 (:0 (KiFastCallEntry))>

<ntdll.dll:d485>

<vncviewer.exe:8b9b4>

<vncviewer.exe:15608>

<vncviewer.exe:4af5d>

<vncviewer.exe:4afe7>

<kernel32.dll:1b3ba>

<00000000>