mail merge

Hi to all

I'm using thunderbird 24 with extension mail merge 3.5.0

The problem is that nothing happens.

I have a set of well-formed csv file (already used some other times).
I checked that the variables are all correctly typed (they are only 3).

When I start mail merge the working window appear for a moment but then e-mails are not created.

I've looked at the error console and find this:

Problema di sicurezza: i contenuti in moz-nullprincipal:{cca63271-9710-4dec-9112-cb8e5f6873f2} non possono caricare o avere link che rimandino a mailbox:///C:/portable/ThunderbirdPortable/Data/profile/Mail/pop.tiscali.it/Templates?number=6833017&header=filter&emitter=js&part=1.2.

That translated can be something smilar to:

Security problem: the contents in moz-nullprincipal: {cca63271-9710-9112-4dec-cb8e5f6873f2} can not load or link, hinting at ...

A can't figure out why and how to resolve it

Someone can help me?

Thanks.