I have submitted my application along with all necessary attachments. The officer in the office gave me a long letter in Polish. My Polish friend translated the letter for me and explained that there is a long list of documents that should be attached to the application. As far as I understand, I have already submitted all of them. What does this letter mean to me?

It’s very good that your friend translated this letter for you. Everyone should ask for help in translating documents in Polish and check once again if they have surely attached all documents from the list. If it turns out that you have forgotten about a document, you must provide it within 14 days. If you are convinced that you have delivered everything, you have nothing to worry about.