VirtualBox IGuestSession::ProcessCreate returns 0x8000FFFF (E_UNEXPECTED)


So I'm trying to execute a process in the guest session from the host, but I keep getting a 0x8000FFFF (E_UNEXPECTED) HRESULT from it. Since I'm getting a COM error rather than VBOX_E_IPRT_ERROR it makes me think my SAFEARRAYs are the issue and not the actual parameters if that makes sense. I'm not too familiar with COM, so it might just be a case of me using SAFEARRAY wrong. Either way, here's the code I'm trying right now:

SAFEARRAY  *args_and_env, *creation_flags;
arrayDim[0].lLbound= 0;
arrayDim[0].cElements= 1;

args_and_env = SafeArrayCreate(VT_LPWSTR,1,arrayDim);
SafeArrayPutElement(args_and_env, 0, L"");

creation_flags = SafeArrayCreate(VT_INT, 1, arrayDim);
int flag = ProcessCreateFlag_None;
SafeArrayPutElement(creation_flags, 0, &flag);

IGuestProcess *proca;
rc = guestSession->ProcessCreate(proc, args_and_env, args_and_env, creation_flags, 0, &proca);

Documentation for IGuestSession::ProcessCreate is as following:

IGuestProcess IGuestSession::processCreate(
[in] wstring executable,
[in] wstring arguments[],
[in] wstring environmentChanges[],
[in] ProcessCreateFlag flags[],
[in] unsigned long timeoutMS)

And the function declaration is as following:

/* [in] */ BSTR aExecutable,
/* [in] */ SAFEARRAY * aArguments,
/* [in] */ SAFEARRAY * aEnvironmentChanges,
/* [in] */ SAFEARRAY * aFlags,
/* [in] */ ULONG aTimeoutMS,
/* [retval][out] */ IGuestProcess **aGuestProcess)

I've also tried passing NULL to both arguments and environmentChanges as I'm not looking to use any of them, but with the same result.

asked on Stack Overflow Oct 18, 2015 by Maddnias

1 Answer


When i tested my task i realized that this problem can be if you use session OS without password. You have to set password and create session with password:

BSTR login = ...;
BSTR passsword = ...;
BSTR empty = SysAllocString(L"");
HRESULT rc = guest->CreateSession(login, password, empty, sessionName, &guestSession); 

And then create a guest process

answered on Stack Overflow Apr 30, 2019 by Range

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