I experienced the same thing when I first tried to use the tool. The issue seems to be that Vertabelo is VERY picky on line ending encodings. Files saved in Notepad++ (no matter whether using CRLF or LF endings) would invariably fail. Files copy and pasted into Notepad and then saved seem to work, even if they DDL looks all run together in Notepad.
Customer support service by UserEcho