Opengl i error 1282

bool LoadTexture(const char* filename)
{
	FIBITMAP* bitmap = FreeImage_Load(
        FreeImage_GetFileType(filename, 0),
        filename);
cout<<glGetError()<<endl;
FIBITMAP *pImage = FreeImage_ConvertTo32Bits(bitmap);
int nWidth = FreeImage_GetWidth(pImage);
int nHeight = FreeImage_GetHeight(pImage);
cout<<nWidth<<endl;
    glGenTextures(1, &tex);

    glBindTexture(GL_TEXTURE_2D, tex);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, nWidth,nHeight,
        0, GL_BGRA, GL_UNSIGNED_BYTE,pImage);
cout<<glGetError()<<endl;

cout<<tex<<endl;
    FreeImage_Unload(bitmap);
}

#pragma once

#include <wincodec.h>
#include <comdef.h>

_COM_SMARTPTR_TYPEDEF(IWICImagingFactory, __uuidof(IWICImagingFactory));
_COM_SMARTPTR_TYPEDEF(IWICBitmapDecoder, __uuidof(IWICBitmapDecoder));
_COM_SMARTPTR_TYPEDEF(IWICBitmapFrameDecode, __uuidof(IWICBitmapFrameDecode));
_COM_SMARTPTR_TYPEDEF(IWICBitmapSource, __uuidof(IWICBitmapSource));
_COM_SMARTPTR_TYPEDEF(IWICFormatConverter, __uuidof(IWICFormatConverter));
_COM_SMARTPTR_TYPEDEF(IWICBitmapFlipRotator, __uuidof(IWICBitmapFlipRotator));

struct CoInit
{
    CoInit() { hr = CoInitialize(NULL); }
    ~CoInit() { if (SUCCEEDED(hr)) CoUninitialize(); }
    HRESULT hr;
};

class CTexLoader
{
public:
    CTexLoader();
    GLuint LoadTexture(const char *fileName);
private:
    CoInit coinit;
    IWICImagingFactoryPtr factory;
    CTexLoader(CTexLoader&) = delete;
};

// ctexloader.cpp
#include "ctexloader.h"

#include <cstdint>
#include <string>
#include <iterator>
#include <vector>
using namespace std;

CTexLoader::CTexLoader()
{
    factory.CreateInstance(CLSID_WICImagingFactory1);
}

GLuint CTexLoader::LoadTexture(const char *fileName)
{
    wstring wFileName(fileName, fileName+strlen(fileName));

    IWICBitmapDecoderPtr decoder;
    factory->CreateDecoderFromFilename(
                wFileName.c_str(),
                NULL,
                GENERIC_READ,
                WICDecodeMetadataCacheOnDemand,
                &decoder);

    if (!decoder)
        return 0;

    IWICBitmapFrameDecodePtr frame;
    decoder->GetFrame(0, &frame);

    IWICBitmapSourcePtr source;
    frame.QueryInterface(IID_PPV_ARGS(&source));

    WICPixelFormatGUID format;
    source->GetPixelFormat(&format);
    if (format != GUID_WICPixelFormat32bppBGRA)
    {
        IWICFormatConverterPtr converter;
        factory->CreateFormatConverter(&converter);
        converter->Initialize(
                    frame,
                    GUID_WICPixelFormat32bppBGRA,
                    WICBitmapDitherTypeErrorDiffusion,
                    (IWICPalette*)NULL,
                    0.0,
                    WICBitmapPaletteTypeCustom);
        converter.QueryInterface(IID_PPV_ARGS(&source));
    }

    UINT w, h;
    source->GetSize(&w, &h);

    vector<uint32_t> bitmap;
    bitmap.resize(w * h);

    IWICBitmapFlipRotatorPtr flip;
    factory->CreateBitmapFlipRotator(&flip);
    flip->Initialize(source, WICBitmapTransformFlipVertical);
    flip.QueryInterface(IID_PPV_ARGS(&source));

    source->CopyPixels(NULL, w*4, w*h*4, (BYTE*)bitmap.data());

    GLuint texture;
    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);

    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, w, h, 0, GL_BGRA, GL_UNSIGNED_BYTE, bitmap.data());

    glBindTexture(GL_TEXTURE_2D, 0);

    return texture;
}

    CTexLoader texLoader;
    t1 = texLoader.LoadTexture("t1a.png");
    t2 = texLoader.LoadTexture("t2a.png");
    // itp.