It would fit rather in post-1900, but have Franz Ferdinand not be shot in 1914, be crowned as Emperor in Vienna in 1916 and refuse to be crowned as Hungarian King, to keep all option open for either an unitarian state or an additional Bohemian-Moravian-Slovakian or an Craoatian-Dalmatian-Bosnian imperial part or a Popovici solution. The Magyar magnats are furious, other groups might be much more positive.
You will not get an immediate full-scale civil war, but domestic troubles, widespread tax boycot and ethnic unrest might spin out of control. Plus, the French, the Italians, the Germans and the Russians (plus Serbians) will all have there own agendas ans try to influence factions inside the monarchy.