Right now these are the known issues. Next to every issue you can see if it has been fixed already.
- Provincia must be uppercase. Fixed in 2.2.26
- Codice Fiscale must be uppercase. Fixed in 2.2.26
- Invoices partially paid with credit are rejected by Revenue Agency. Fixed in 2.2.26
- Rounding amounts sometime cause errors. Fixed in 2.2.27