Minecraft Launcher Error

Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
Error: Could not find or load main class net.minecraft.client.main occurs whenever I try to open my MC launcher. Keep in mind, I have a mac OSX version 10.7.5, and I already downloaded java 8, I am not sure what the problem is. In additon too that, since my computer is too old, it doesn't allow me to download the newest launcher, and I am very frustrated by this event. Been researching for hours on how to fix this, but no luck, can anyone place come through and find a simple solution please?

Thanks, Edmund.