How to Fix Mac OS X Yosemite 10.10 Messages Crash: Internal Messages error occurred

Got this error message on Mac OS X Yosemite when opening the Messages app:

An internal Messages error occurred.

There was a problem with Messages.

You need to quit and open Messages again

Fix this by:

1. Open contacts app

2. Disable all the accounts you have there (iCloud, Google, etc..)

3. Now you have no contacts in your contacts list

4. Open Messages app

Now the Mac OS X Yosemite 10.10 Messages App works!