I managed to get the game working again. My problem was game "hanging on screen" when custom song loads. Beta method not worked for me.
Here's what I did.
Uninstall game (save custom songs to other folder and delete whole Rocksmith-folder)
Install game on steam
Copy custom songs back
Install rs_asio ((https://github.com/mdias/rs_asio/releases/tag/v0.6.1) if needed, I've got Focusrite 2i2 3rd gen) and setup rs_asio.ini for your interface.
Install CDLC-enabler (https://ignition4.customsforge.com/tools/CDLCEnabler). This will also install new D3DX9_42.dll on rocksmith-folder. Setup rs-asio.ini if you installed rs-asio.
Start game and it should work.