Field scripts not running on customer portal

[Mario Stoilov]

I have a behavior script, very simple:

def tpvField = getFieldById(getFieldChanged())
tpvField.setError("Why am I not running?")

It is attached to a field. The mapping is both for the customer portal and agent view (project and portal mapping). This script runs when browsing the agent view, but not on the customer portal, and I cannot find out why. Using the "read-only", "visible" and "editable" toggles works, but the script doesn't.

Can anybody lend a hand? Where do I need to check, where can I find logs, is there a configuration I need to check?