tst_qmediaplayerbackend crash on windows 7 & 10

agent:2018/09/25 07:36:25 build.go:193: 	call C:\Users\qt\work\qt\qtmultimedia\tests\auto\integration\qmediaplayerbackend\target_wrapper.bat  release\tst_qmediaplayerbackend.exe -o C:\Users\qt\work\testresults\tests\auto\integration\qmediaplayerbackend878674964,xml -o -,txt
agent:2018/09/25 07:36:25 build.go:193: ********* Start testing of tst_QMediaPlayerBackend *********
agent:2018/09/25 07:36:25 build.go:193: Config: Using QtTest library 5.12.0, Qt 5.12.0 (x86_64-little_endian-llp64 shared (dynamic) release build; by MSVC 2015)
agent:2018/09/25 07:36:26 build.go:193: PASS   : tst_QMediaPlayerBackend::initTestCase()
agent:2018/09/25 07:36:26 build.go:193: BPASS  : tst_QMediaPlayerBackend::construction()
agent:2018/09/25 07:36:26 build.go:193: BFAIL  : tst_QMediaPlayerBackend::loadMedia() 'player.isAudioAvailable()' returned FALSE. ()
agent:2018/09/25 07:36:26 build.go:193: tst_qmediaplayerbackend.cpp(255) : failure location
agent:2018/09/25 07:36:26 build.go:193: BFAIL  : tst_QMediaPlayerBackend::unloadMedia() 'player.duration() > 0' returned FALSE. ()
agent:2018/09/25 07:36:26 build.go:193: tst_qmediaplayerbackend.cpp(279) : failure location
agent:2018/09/25 07:36:31 build.go:193: A crash occurred in C:\Users\qt\work\qt\qtmultimedia\tests\auto\integration\qmediaplayerbackend\release\tst_qmediaplayerbackend.exe.
agent:2018/09/25 07:36:31 build.go:193: Function time: 4013ms Total time: 5076ms
agent:2018/09/25 07:36:31 build.go:193: 
agent:2018/09/25 07:36:31 build.go:193: Exception address: 0x00007FFAB510C344
agent:2018/09/25 07:36:31 build.go:193: Exception code   : 0xc0000005
agent:2018/09/25 07:36:31 build.go:193: Nearby symbol    : AMGetErrorTextW
agent:2018/09/25 07:36:31 build.go:193: 
agent:2018/09/25 07:36:31 build.go:193: Stack:
agent:2018/09/25 07:36:31 build.go:193: #  1: TestNamespace::QTest::toString() - 0x00007FFACCE3A570
agent:2018/09/25 07:36:31 build.go:193: #  2: UnhandledExceptionFilter() - 0x00007FFAD44A67C0
agent:2018/09/25 07:36:31 build.go:193: #  3: memset() - 0x00007FFAD745BE40
agent:2018/09/25 07:36:31 build.go:193: #  4: _C_specific_handler() - 0x00007FFAD74463D0
agent:2018/09/25 07:36:31 build.go:193: #  5: _chkstk() - 0x00007FFAD7459F60
agent:2018/09/25 07:36:31 build.go:193: #  6: RtlLookupFunctionEntry() - 0x00007FFAD73C91A0
agent:2018/09/25 07:36:31 build.go:193: #  7: KiUserExceptionDispatcher() - 0x00007FFAD74590D0
agent:2018/09/25 07:36:31 build.go:193: #  8: AMGetErrorTextW() - 0x00007FFAB5055EE0
agent:2018/09/25 07:36:31 build.go:193: #  9: CoInternetCombineUrlEx() - 0x00007FFAC9F37900
agent:2018/09/25 07:36:31 build.go:193: # 10: Ordinal519() - 0x00007FFAC9F07100
agent:2018/09/25 07:36:31 build.go:193: # 11: Ordinal519() - 0x00007FFAC9F07100
agent:2018/09/25 07:36:31 build.go:193: # 12: Ordinal519() - 0x00007FFAC9F07100
agent:2018/09/25 07:36:31 build.go:193: # 13: Ordinal521() - 0x00007FFAC9F04180
agent:2018/09/25 07:36:31 build.go:193: # 14: Ordinal519() - 0x00007FFAC9F07100
agent:2018/09/25 07:36:31 build.go:193: # 15: CoInternetIsFeatureEnabled() - 0x00007FFAC9F2E2D0
agent:2018/09/25 07:36:31 build.go:193: # 16: UrlmonCleanupCurrentThread() - 0x00007FFAC9F497E0
agent:2018/09/25 07:36:31 build.go:193: # 17: CallWindowProcW() - 0x00007FFAD6B1B780
agent:2018/09/25 07:36:31 build.go:193: # 18: DispatchMessageW() - 0x00007FFAD6B1B420
agent:2018/09/25 07:36:31 build.go:193: # 19: AMGetErrorTextW() - 0x00007FFAB5055EE0
agent:2018/09/25 07:36:31 build.go:193: # 20: BaseThreadInitThunk() - 0x00007FFAD7312760
agent:2018/09/25 07:36:31 build.go:193: # 21: RtlUserThreadStart() - 0x00007FFAD7420D30
agent:2018/09/25 07:36:31 build.go:193: 
agent:2018/09/25 07:36:31 build.go:193: jom: C:\Users\qt\work\qt\qtmultimedia\tests\auto\integration\qmediaplayerbackend\Makefile.Release [check] Error 2
agent:2018/09/25 07:36:31 build.go:193: jom: C:\Users\qt\work\qt\qtmultimedia\tests\auto\integration\qmediaplayerbackend\Makefile [release-check] Error 2
agent:2018/09/25 07:36:31 build.go:237: Process finished with error: exit status 2
agent:2018/09/25 07:36:31 build.go:435: Executing scheduled instruction 1 of 2 - Upload all core dumps if there are some
agent:2018/09/25 07:36:31 build.go:437: 
agent:2018/09/25 07:36:31 build.go:435: Executing scheduled instruction 2 of 2 - Upload test results
agent:2018/09/25 07:36:31 storageclient.go:540: Collecting test results, archiving and uploading them
agent:2018/09/25 07:36:31 build.go:196: Error reading from stdout/err: exit status 2