I installed an Expansion pack, and nothing new appears neither in Sound or Scene mode.

This error may occur on Windows systems only.

Please copy this file:

 C:\Users\<username>\AppData\Local\VirtualStore\ProgramData\Arturia\Analog Laboratory\Laboratory.db3

into this folder:

 C:\ProgramData\Arturia\Analog Laboratory\

then delete this whole folder:
 C:\Users\<username>\AppData\Local\VirtualStore\ProgramData\Arturia\

Now reinstall the latest version of the synthesizer:
==> http://www.arturia.net/downloads/analoglaboratory/version/latest/Analog_Laboratory_Setup.exe

Launch it and have a test.