Why EnumProcessModules is return FALSE value and 299 code error?

I looked through similar questions, but did not find a solution to my problem.

Exception class:

class Exception{
    public:
        Exception(LPCWSTR text){
            QMessageBox::information(0, "Catch",
                                     QString::fromWCharArray(text) + ", Code: " +
                                     QString::number(GetLastError())); 
                     //EnumModules is return FALSE in function getHinstance, Code: 299
        }
}

And main code:

    HANDLE handle = OpenProcess(PROCESS_ALL_ACCESS, TRUE, 7068); //PID of opened calculator
    if(handle == INVALID_HANDLE_VALUE)
        throw Exception(L"invalid handle in function getHinstance");

    int hNeeded = 1024;
    HINSTANCE hModules[hNeeded];
    DWORD bNeeded = 0;
    PWSTR fileName = new WCHAR[512];
    if(!EnumProcessModulesEx(handle, hModules, sizeof(hModules), &bNeeded, LIST_MODULES_ALL))
        throw Exception(L"EnumModules is return FALSE in function getHinstance");

    for(int i = 0; i < bNeeded / sizeof(HINSTANCE); ++i){
        GetModuleBaseNameW(handle, hModules[i], fileName, sizeof(WCHAR) * 512);
        if(lstrcmpW(fileName, moduleName) == 0){
            delete [] fileName;
            return hModules[i];
        }
    }

handle is a valid value of handle process

This code executes in a 64 bit process to enum modules in a 64 bit process

Solution

I can reproduce ERROR_PARTIAL_COPY (299) error when running the following code as a 64 bit process.

HANDLE handle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, 17152); //PID of opened notepad.exe
DWORD errCode = GetLastError();

HMODULE hModules[100];
DWORD bNeeded = 0;
EnumProcessModulesEx(handle, hModules, sizeof(hModules), &bNeeded, LIST_MODULES_ALL);
errCode = GetLastError();

And solve the error when use LIST_MODULES_64BIT instead of LIST_MODULES_ALL.

My notepad.exe is a 64 bit process.

So it seems you need use LIST_MODULES_64BIT for enumerating the modules of a 64-bit process when use EnumProcessModulesEx.

Or you can use EnumProcessModules:

EnumProcessModules(handle, hModules, sizeof(hModules), &bNeeded);