MinGW Qt and LoadLibrary error: 193

[ispovedn1k]

It's my first attempt to make a plugin. So...

My question is
What sould I do to build my project correctly with mingw and get plugin (I want to make it for both x64 and x32 windows and linux) workable?

I started from very beginning. Simpliest plugin with config form.
clock_alarm.h

#include "ts3_functions.h"

#ifndef CLOCK_ALARM_H_
#define CLOCK_ALARM_H_

#ifdef WIN32
#define PLUGINS_EXPORTDLL __declspec(dllexport)
#else
#define PLUGINS_EXPORTDLL __attribute__ ((visibility("default")))
#endif

#ifdef __cplusplus
extern "C" {
#endif

/* Required functions */
PLUGINS_EXPORTDLL const char* ts3plugin_name();
PLUGINS_EXPORTDLL const char* ts3plugin_version();
PLUGINS_EXPORTDLL int ts3plugin_apiVersion();
PLUGINS_EXPORTDLL const char* ts3plugin_author();
PLUGINS_EXPORTDLL const char* ts3plugin_description();
PLUGINS_EXPORTDLL void ts3plugin_setFunctionPointers(const struct TS3Functions funcs);
PLUGINS_EXPORTDLL int ts3plugin_init();
PLUGINS_EXPORTDLL void ts3plugin_shutdown();

PLUGINS_EXPORTDLL int ts3plugin_offersConfigure();
PLUGINS_EXPORTDLL void ts3plugin_configure(void* handle, void* qParentWidget);
PLUGINS_EXPORTDLL void ts3plugin_registerPluginID(const char* id);


#ifdef __cplusplus
}
#endif

#endif

clock_alarm.h

/**
All content of this file was copied from example source of pluginsdk
the only function I have modified:
*/
int ts3plugin_offersConfigure() {
    printf("PLUGIN: offersConfigure\n");

    return PLUGIN_OFFERS_CONFIGURE_QT_THREAD;
}

It was succesflly compilled to dll. TS3 recognized it as plugin. Welldone.
Then I added a form made by QtCreator.
cformclocksettings.h

#ifndef CFORMCLOCKSETTINGS_H
#define CFORMCLOCKSETTINGS_H

#include <QtGlobal>
#include <QDialog>

namespace Ui {
class CFormClockSettings;
}

class CFormClockSettings : public QDialog
{
    Q_OBJECT

public:
    explicit CFormClockSettings(QWidget *parent = 0);
    ~CFormClockSettings();

private:
    Ui::CFormClockSettings *ui;
};

#endif // CFORMCLOCKSETTINGS_H

cformclocksettings.cpp

#include "cformclocksettings.h"
#include "ui_cformclocksettings.h"

CFormClockSettings::CFormClockSettings(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::CFormClockSettings)
{
    ui->setupUi(this);
}

CFormClockSettings::~CFormClockSettings()
{
    delete ui;
}

cformclocksettings.ui is much longer so lets leave it out. It's empty dialog form with two buttons: "Ok" and "Cancel" and one label as "Hello world!".

din.pro

QT       += \
    widgets

#INCLUDEPATH += ./ts3_include

TARGET = din
TEMPLATE = lib
CONFIG  += qt dll shared plugin

DEFINES += DIN_LIBRARY

SOURCES += \
    clock_alarm.cpp \
    cformclocksettings.cpp

HEADERS +=\
    clock_alarm.h \
    cformclocksettings.h

unix {
    target.path = /usr/lib
    INSTALLS += target
}

FORMS += \
    cformclocksettings.ui

And I've got trouble here...
It successfully compiled to dll. But TS3 doesn't want to work with it any more.
From TS log files I've got that:

Failed to load plugin: C:\Program Files (x86)\TeamSpeak 3 Client\plugins\din.dll
LoadLibrary error: 193

I've tried to plug it to both versions of TS (x64, x32), nothing changed.
That form wasn't even called, and plugin doesn't work already!


Then I installed Visual Studio 2013 to get one more compiler.
Hm...
It compiled version suitable for TS3_x64. Ok, my code is correct... maybe...

My stuffs:
windows 8.1
mingw from http://www.mingw.org/ current mingw32-gcc vesion 4.8.1-4
qt from http://www.qt.io/ru/download/
it's QtCreator version 3.3.2
and Qt version 5.4.1
Visual Studio 2013 (to get one more compiler)
TS3 version 3.0.16 x32 & x64 (Qt 5.2.1)

I'm noob in Qt and plugin development. Is there any magic in it?