Trouble with USB FS CDC on STMf3discovery. initialization problem.

[hashtala]

Hello

I generated project with cubeMX. When I fired it up PC recognizec STM32 Board as virtual COM. But it would never work. When I used Transmit function it would always freeze on USBD_BUSY

Now what I have found is that when I do initialization it never gets do Configured mode, rather it gets into USBD_Default. Have no idea why

Then I generated HID project, with exact same settings (I know heap and stack sizes issue). It worked perfectly. It went to USBD_Configured immediately.

What could be causing CDC mode to do in Default and not get assigned address and everything?