Not able to use unlimited emfileds

When setting unlimited video emfields (or image, or both) (not being required), I cannot save the new node.

It reloads the edit page, no error message is given and it adds a new empty field (image or video, whichever is first in the edit form).

So... when creating the node, two emfields and the add another button appear. When I save the node, it goes back to the edit form and three emfields appear this time. If I try again, same happens but with four emfields.

I have been trying and realised that this happens even whith the emfields set to one if the upload module is enabled