Complex sentence: F.C. United were ineligible to play in the FA Vase for their first season as the club was formed after the deadline to enter the competition; they were, however, able to play in the North West Counties League Challenge Cup.
Split into simpler sentences: F.C. United were ineligible to play in the FA Vase for their first season because the club was formed after the deadline to enter the competition. They were, however, able to play in the North West Counties League Challenge Cup.