Thank you Lat9. I also installed latest Github version and got rid of Integer errors.

Main reason I could not make exports to subcategories was that I had 2 same named categories the old one without subcategories was BARRACUDA and the new which had right subcategories was named Barracuda. The db-connection query does not see any difference between them and because I had "make categories from csv" turned off it could not make categories to old BARRACUDA folder either. Lat9 spotted that. Thank you to her very much! I have now bulk imported over 1500 products to ZC with DbIo without any problems.