Hello Massimo Florido.
When you get this error there are many issue, the main one is the Ajax.
If you don't mess around with the templates, go to the Form, check each field and click the Ajax Tab, and make sure your Enable Events are disable or check if in the Ajax Tab Event Flow has something.
Or check if the selector has entity selected.
By Default Webratio doesn't have error in the putAll() method.
I got this issue many times.