[Flow] Strange Exception when migrating DB

[Christian Loock]

Hi,

when I run doctrine:create i get the following exception:

   No class schema found for "Doctrine\Common\Collections\Collection". The
   class should probably marked as entity or value object!

What exactly is a class schema.

Can anybody hint me into a direction to investigate this?

The error itself does not really help at all.

Greetings,

Christian