logic 10.2.1 keeps crashing on startup?

Hi

After the latest update for Logic Pro 10.2.1, my system kept crashing on startup, it was driving me crazeeeeee!

so I found a fix:

1. I set up a new user profile for administration

2. Logic worked here! So I copied the logic folder from my main hard drive - library/application support/logic - onto an external hard drive

3. I ALSO copied the logic folder from - Users/my name/music/logic - to the hard drive

4. I went back to my main account and replaced the folders there with these folders

5. On my main account I then went to users/myname/music/audiomusicapps/databases and deleted this folder

6. I then re-installed Yosemite

ALL RUNNING LIKE A HOT ROD.......PHEW - NEXT TIME I WILL BACK UP PROPERLY WITH TIME MACHINE!!