Background: Jan Zizka z Trocnova a Kalicha (Czech pronunciation: ['jan 'ZISka] ( listen); German: Johann Ziska; English: John Zizka of Trocnov and the Chalice) was a Czech general, a contemporary and follower of Jan Hus, Hussite military leader, and later also a Radical Hussite who led the Taborites. Zizka is held to be one of the most renowned military leaders by many historians and today he is widely considered a Czech national hero. He was born in the small village of Trocnov (now part of Borovany) in the Kingdom of Bohemia into an aristocratic family.
Context: Early in 1423, internal dissent among the Hussites led to civil war. Zizka, as leader of the Taborites, defeated the men of Prague and the Utraquist nobles at Horice on April 20. Shortly afterwards came news that a new crusade against Bohemia was being prepared. This induced the Hussites to conclude an armistice at Konopiste on June 24. As soon as the crusaders had dispersed, internal dissent broke out anew. During his temporary rule over Bohemia, Prince Sigismund Korybut of Lithuania had appointed Borek, the lord of Miletinek, governor of the city of Hradec Kralove. Borek belonged to a moderate Hussite faction, the Utraquist party. After the departure of Sigismund Korybut, the city of Hradec Kralove refused to recognize Borek as its ruler, due to the democratic party gaining the upper hand. They called Zizka to its aid. He acceded to the demand and defeated the Utraquists under Borek at the farm of Strachov, near the city of Hradec Kralove on August 4, 1423.  Zizka now attempted to invade Hungary, which was under the rule of his old enemy King Sigismund. Though this Hungarian campaign was unsuccessful owing to the great superiority of the Hungarians, it ranks among the greatest military exploits of Zizka, on account of the skill he displayed in retreat. In 1424, civil war having again broken out in Bohemia, Zizka decisively defeated the "Praguers" and Utraquist nobles at Skalice on January 6, and at Malesov on June 7. In September, he marched on Prague. On the 14th of that month, peace was concluded between the Hussite parties through the influence of John of Rokycany, afterwards Utraquist archbishop of Prague. It was agreed that the now reunited Hussites should attack Moravia, part of which was still held by Sigismund's partisans, and that Zizka should be the leader in this campaign. However, he died of the plague at Pribyslav on October 11, 1424 on the Moravian frontier. According to chronicler Piccolomini, Zizka's dying wish was to have his skin used to make drums so that he might continue to lead his troops even after death. Zizka was so well regarded that when he died, his soldiers called themselves the Orphans (sirotci) because they felt like they had lost their father. His enemies said that "The one whom no mortal hand could destroy was extinguished by the finger of God."  He was succeeded by Prokop the Great.
Question: what caused the civil war?

Answer:
internal dissent among the Hussites