I closed the project first and then clicked the X in the top right corner

This really seems to be a driver issue.  Do you have the latest drivers installed for your internal sound card?  It looks like you also have a Scarlett 2i2.  Does this problem happen when you are using the Scarlett for output or just when using your internal card?
 
Glen

JimmyBoy
I closed the project first and then clicked the X in the top right corner

Yup step 10 was noted. Environmental issue I suggest.
Try temporarily turning off your antivirus and stopping services that are not required, and what Glen says.

I Just tried again the same steps, this time using Z3TA+2 as the audio for the output of the midi tracks and have the same problem, and similar finger print of the process dump...
 
I'll see if I can replicate this on my other PC,  Probably get the chance to try this later in the week.
 
Here is the wdmaud driver details

0:000> !lmi wdmaud
Loaded Module Info: [wdmaud] 
         Module: wdmaud
   Base Address: 00007ff9038e0000
     Image Name: wdmaud.drv
   Machine Type: 34404 (X64)
     Time Stamp: 5215dbdc Thu Aug 22 19:37:32 2013
           Size: 3c000
       CheckSum: 39dfd
Characteristics: 2022  perf
Debug Data Dirs: Type  Size     VA  Pointer
             CODEVIEW    23, 2cb28,   2bf28 RSDS - GUID: {63BD5149-2828-4F20-A000-25FBDF3C325E}
               Age: 2, Pdb: wdmaud.pdb
                CLSID     8, 2cb20,   2bf20 [Data not mapped]
     Image Type: MEMORY   - Image read successfully from loaded memory.
    Symbol Type: PDB      - Symbols loaded successfully from image header.
                 C:\ProgramData\dbg\sym\wdmaud.pdb\63BD514928284F20A00025FBDF3C325E2\wdmaud.pdb
    Load Report: public symbols , not source indexed 
                 C:\ProgramData\dbg\sym\wdmaud.pdb\63BD514928284F20A00025FBDF3C325E2\wdmaud.pdb

 
Here is the latest stack

ntdll!NtWaitForSingleObject+0xa:
00007ff9`0e1565ba c3              ret
 
FOLLOWUP_IP: 
wdmaud!CWAVRenderer::FreeResources+8f
00007ff9`038f8dbb 488b4f10        mov     rcx,qword ptr [rdi+10h]
SYMBOL_STACK_INDEX:  2
SYMBOL_NAME:  wdmaud!CWAVRenderer::FreeResources+8f
FOLLOWUP_NAME:  MachineOwner
MODULE_NAME: wdmaud
IMAGE_NAME:  wdmaud.drv
DEBUG_FLR_IMAGE_TIMESTAMP:  5215dbdc
FAILURE_BUCKET_ID:  STATUS_BREAKPOINT_80000003_wdmaud.drv!CWAVRenderer::FreeResources
BUCKET_ID:  APPLICATION_FAULT_STATUS_BREAKPOINT_DETOURED_wdmaud!CWAVRenderer::FreeResources+8f
ANALYSIS_SOURCE:  UM
FAILURE_ID_HASH_STRING:  um:status_breakpoint_80000003_wdmaud.drv!cwavrenderer::freeresources
FAILURE_ID_HASH:  {f3a7a38e-87f6-a176-21b2-387e3e8aa129}
 
0:000> k
Child-SP          RetAddr           Call Site
00000000`0013fb48 00007ff9`0b661148 ntdll!NtWaitForSingleObject+0xa
00000000`0013fb50 00007ff9`038f8dbb KERNELBASE!WaitForSingleObjectEx+0x94
00000000`0013fbf0 00007ff9`038f9280 wdmaud!CWAVRenderer::FreeResources+0x8f
00000000`0013fc20 00007ff9`038f7771 wdmaud!CWAVRenderer::Shutdown+0x10
00000000`0013fc50 00007ff9`038f7aed wdmaud!CMIDISynthTask::MODMClose+0x1e
00000000`0013fc80 00007ff9`038ec2f4 wdmaud!SwModMessage+0xb5
00000000`0013fcb0 00007ff9`075b6cc4 wdmaud!CBusIds::CBusIds+0x2818
00000000`0013fcf0 00000001`403c4426 WINMMBASE!midiOutClose+0x9c
00000000`0013fd30 00000001`403c43d4 SONARSTD+0x3c4426
00000000`0013fd70 00000001`403c6334 SONARSTD+0x3c43d4
00000000`0013fda0 00000001`4038748b SONARSTD+0x3c6334
00000000`0013fdd0 00000001`405995af SONARSTD+0x38748b
00000000`0013fe00 00000001`40596ed7 SONARSTD+0x5995af
00000000`0013feb0 00007ff8`ec9acf4a SONARSTD+0x596ed7
00000000`0013fee0 00000001`404aa6f6 mfc110u!AfxWinMain+0xa6
00000000`0013ff20 00007ff9`0b9515cd SONARSTD+0x4aa6f6
00000000`0013ff60 00007ff9`0e1343d1 kernel32!BaseThreadInitThunk+0xd
00000000`0013ff90 00000000`00000000 ntdll!RtlUserThreadStart+0x1d

Yup can't reproduce, BTW I doubt stacks dumps are going to resolve your issue much, this may help if there is a file locking issue: http://technet.microsoft.com/en-gb/sysinternals/bb896645
 
However please try out what has been suggested earlier first.

Yeah, I'll try procmon - will also try uninstalling and then re-installing Audio driver on notebook

To add I would also say disable any antivirus or any debugging tools as that can lock processes first.

is it possible ASIO4ALL is hanging up after the project closes ?
if sonar is using that as your soundcard driver and you exit but it is still running with a project it may cause a hang,
especially considering ASIO4ALL hasn't had any official updates in years and running windows 8.1 has never been tested with it.
 
you can try a test by switching your driver mode to MME (only to test) and see if you can reproduce the hang.

Good point, though just tried it, changed ASIO for MME, played then saved and closed and it does the same thing...
I might hit the MS Folks on this one and see what they suggest - I'm thinking uninstall audio driver and re-install it..
 

FOLLOWUP_IP: 
wdmaud!CWAVRenderer::FreeResources+8f
00007ff8`fb7c8dbb 488b4f10        mov     rcx,qword ptr [rdi+10h]
SYMBOL_STACK_INDEX:  2
SYMBOL_NAME:  wdmaud!CWAVRenderer::FreeResources+8f
FOLLOWUP_NAME:  MachineOwner
MODULE_NAME: wdmaud
IMAGE_NAME:  wdmaud.drv
DEBUG_FLR_IMAGE_TIMESTAMP:  5215dbdc
FAILURE_BUCKET_ID:  STATUS_BREAKPOINT_80000003_wdmaud.drv!CWAVRenderer::FreeResources
BUCKET_ID:  APPLICATION_FAULT_STATUS_BREAKPOINT_DETOURED_wdmaud!CWAVRenderer::FreeResources+8f
ANALYSIS_SOURCE:  UM
FAILURE_ID_HASH_STRING:  um:status_breakpoint_80000003_wdmaud.drv!cwavrenderer::freeresources
FAILURE_ID_HASH:  {f3a7a38e-87f6-a176-21b2-387e3e8aa129}
Followup: MachineOwner
---------
0:000> k
Child-SP          RetAddr           Call Site
00000000`0013fb48 00007ff9`0b661148 ntdll!NtWaitForSingleObject+0xa
00000000`0013fb50 00007ff8`fb7c8dbb KERNELBASE!WaitForSingleObjectEx+0x94
00000000`0013fbf0 00007ff8`fb7c9280 wdmaud!CWAVRenderer::FreeResources+0x8f
00000000`0013fc20 00007ff8`fb7c7771 wdmaud!CWAVRenderer::Shutdown+0x10
00000000`0013fc50 00007ff8`fb7c7aed wdmaud!CMIDISynthTask::MODMClose+0x1e
00000000`0013fc80 00007ff8`fb7bc2f4 wdmaud!SwModMessage+0xb5
00000000`0013fcb0 00007ff9`075b6cc4 wdmaud!CBusIds::CBusIds+0x2818
00000000`0013fcf0 00000001`403c4426 WINMMBASE!midiOutClose+0x9c
00000000`0013fd30 00000001`403c43d4 SONARSTD+0x3c4426
00000000`0013fd70 00000001`403c6334 SONARSTD+0x3c43d4
00000000`0013fda0 00000001`4038748b SONARSTD+0x3c6334
00000000`0013fdd0 00000001`405995af SONARSTD+0x38748b
00000000`0013fe00 00000001`40596ed7 SONARSTD+0x5995af
00000000`0013feb0 00007ff8`ec9acf4a SONARSTD+0x596ed7
00000000`0013fee0 00000001`404aa6f6 mfc110u!AfxWinMain+0xa6
00000000`0013ff20 00007ff9`0b9515cd SONARSTD+0x4aa6f6
00000000`0013ff60 00007ff9`0e1343d1 kernel32!BaseThreadInitThunk+0xd
00000000`0013ff90 00000000`00000000 ntdll!RtlUserThreadStart+0x1d

Hi
 
I'm just learning X3 Studio.  I have the same issue with Sonar continuing to run in the background after I exit it unless I exit via the Task Manager.  Just emailed tech support and they have no answers.  This happens for me no matter what I use for drivers or even if I don't have a device connected.  All I have to do is open a project, old or new and try to exit through the File menu or X in the upper right screen.  The only thing I don't like about this is that in this way, you're not asked if you want to save your changes.  I guess it's a bug they have to fix.
 
John B.