What was the problem austria-hungary was dealing with in serbia before the 1914?

Before 1914, Austria-Hungary was concerned about the rise of nationalism in Serbia, which threatened its own stability, particularly among its Slavic populations. The assassination of Archduke Franz Ferdinand in June 1914 by a Bosnian Serb nationalist further intensified these tensions, leading Austria-Hungary to view Serbia as a direct threat. Austria-Hungary sought to assert its influence in the Balkans and curb Serbian nationalism, which ultimately contributed to the outbreak of World War I.