There is a bug with it, I don't know why yet. Last proforma I wrote the previous month was #41, then of course I accepted some payments, these proforma invoices got converted to a normal invoices, and I've tried to create proforma yesterday. It got #0 assigned. Yes, 0, that's not a mistake That's why I ask Blesta developers if they're going to fix that in 3.5, because they haven't fixed it in 3.4.2. Without EU invoicing we cannot use Blesta billing.