Why is Minecraft Forge 1.7.2 not working?

Each time I start Minecraft with 1.7.2 Forge, the start screen becomes pixelated and there are random things in the pixels that have nothing to do with Minecraft, for example pieces of the start screen and desktop image. I tried restarting the computer but that didn't help either. I can still start Minecraft with the regular versions, only Forge creates this glitch. Please help! I'm so exhausted trying to find a reason for this.

P.S.: I use mac

Guest

Did you use the right version or forge? I installed mods for the first time today, so I know how tricky it can be. According to my research it was recommend to delete the.minecraft folder (backup your saves) and start over. Once you've done that open the launcher and click "new profile". From there select version 1.7.2. Once you've done that go to files.minecraftforge.net and download forge 1.7.2 (the one that says recommended nest to it).

Winter puppy