[Tree] - troubles with lft column

[enricostano]

I was following this (http://www.gediminasm.org/article/tree-nestedset-behavior-extension-for-doctrine-2) tutorial and I get this error while creating new object:

SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'lft' cannot be null

here is my class: https://gist.github.com/2795629

and the controller: https://gist.github.com/2795632

thank you

[l3pp4rd]

the tree extension listener is not active if you get such error. read the documentation on you to install extensions. if you use stof bundle, enable tree

[enricostano]

Solved, thank you!