Could not find or load main class.

I've recently been given this error*. I do use the old version of the launcher. Secondly, would there be a way to not push the update to the new Launcher, or is this to push the update ?

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