[FLOW3-general] Problems upgrading to 1.0

[Ivan Ruiz Gallego]

Hi everyone,

I've upgraded FLOW3 from beta 2 to 1.0. The migration script for the new 
annotation syntax worked like a charm (thank you!). But, I still get the 
following fatal error:

Fatal error: Class 'Symfony\Component\Yaml\Yaml' not found in 
/var/www/vhosts/lions/Packages/Framework/TYPO3.FLOW3/Classes/Configuration/Source/YamlSource.php 
on line 35

Has someone a clue where the problem is?

Thanks,
Ivan.