Messages.app crashing

[OSX 10.9]

Hello everyone,

I was changing my font on the Messages.app application on my iCloud (iMessage) account to the "Apple Color Emoji" font, then I quit the application and when I wanted to open it again, I have those errors :

http://d.pr/i/Efi4

Then whatever the button I click, I have this error :

http://d.pr/i/FjbZ

I already tried to delete every related iChat/Messages.app .plist files on " /Users/[MyUser]/Library/Preferences/ ", but I am still having the same problem.

On the Console log, I can see that the problem is really related to the fon I selected :

Application Specific Information:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** setObjectForKey: object cannot be nil (key: NSFont)'

terminating with uncaught exception of type NSException

abort() called

I'd be really happy to have a solution to this !

Thanks !