Java Error New Launcher

I have enough RAM on my pc and everytime when i try to start Minecraft at DEV launcher it says:

YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----

YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----

YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----

(We'll do this automatically later ;D) ----
Client> Error occurred during initialization of VM
Client> Could not reserve enough space for object heap
Client> Error: Could not create the Java Virtual Machine.
Client> Error: A fatal exception has occurred. Program will exit.

Fix please.