Thank you for your post.
FileMaker Pro is encountering something in the CSV file that makes it stop importing. Find the last imported record in the FileMaker Pro table, and then find the information in the CSV file. Either the end of that record or the next record in the CSV file is probably causing FileMaker Pro to stop importing. If you don't see anything wrong, try splitting the CSV file into two parts; the part that imports (150,000 records) and the remaining part to import (1,150,000 records).
Please let me know if you should run into any further difficulties.