Issue launching custom modpack || Installation Corrupt

[Siriuo]

Hello,

I am having some issues launching a custom 1.5.1 modpack. I am receiving an error message on screen which says:

Your Minecraft installation is corrupt, but has been cleaned.

Try to login again.

If that fails, close and restart the application.

I have tried to restart the application with no success.

Are there any solutions

Solution: I found out that I was using an incorrect version of Forge for 1.5.2 instead of 1.5.1