ERR_MEMORY-not enough memory or resources

I’m trying to move my project from Fmod Ex to Unity. The code was worked fine in Ex, but not in Unity. The code looks like:

using UnityEngine;
using System.Collections;
using FMOD;

public class _Oscillators : MonoBehaviour {

    FMOD.RESULT Fresult; 
    FMOD.System Fsystem; 
    FMOD.DSP Fdsp;
    FMOD.Channel Fchannel;
    FMOD.ChannelGroup Fchannelgroup;
    System.IntPtr ptr;

	// Use this for initialization
	void Start () {

        ptr = new System.IntPtr();
        Fsystem = new FMOD.System(ptr);
        Fresult = new FMOD.RESULT();


        Fchannel = new FMOD.Channel(ptr);
        Fdsp = new FMOD.DSP(ptr);

        Fresult = Fsystem.createDSPByType(DSP_TYPE.OSCILLATOR, out Fdsp);

        Fresult = Fdsp.setParameterInt((int)DSP_OSCILLATOR.TYPE, 0);
        Fresult = Fdsp.setParameterInt((int)DSP_OSCILLATOR.RATE, 220);

        Fresult = Fsystem.playDSP(Fdsp, null, false, out Fchannel);

        Fresult = Fchannel.setVolume(1.0f);


    private void FMOD_Initialize()
        Fresult = FMOD.Factory.System_Create(out Fsystem);
        ERRCHECK(Fresult, "create system");


    private void FMOD_DeInitialize()
        Fresult = Fsystem.close();
        ERRCHECK(Fresult, "close");

    private void ERRCHECK(FMOD.RESULT Fresult, string comment)
        if (Fresult != FMOD.RESULT.OK)
            UnityEngine.Debug.Log ("FMOD error in " + comment + ": " + Fresult + "-" + FMOD.Error.String(Fresult));

Unfortunately, at FMOD.Factory.System_Create(out Fsystem) it gives an ‘ERR_MEMORY-not enough memory or resources’ message. What am I doing wrong?

There is a maximum of 8 system objects that can be created. After you’ve hit that limit FMOD.Factory.System_Create() will return ERR_MEMORY.

The problem is that even if I just add FMOD_Listener (FMOD native script), the error message still has appeared. It seems that I can’t use FMOD in Unity (mine is 4.5.4 Pro) at all? By the way, when I use a SquareTangle implementation, all works fine. Unfortunately, I need some features from the original asset. Any suggestions?