Could not find or load main class net.minecraft.client.main.Main

What I expected to happen was...:
To see an error from 1.9!
What actually happened was...:
See a new error that prevent me to even open the game window
And now I see

Error: Could not find or load main class net.minecraft.client.main.Main
Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release