I will call TK when they open in the U.S. But I know they did not cancel my flight, the flight is still operating. All that was canceled was my reservation. I'll still call and try to get any info from TK before calling UA.

Per the other thread, after I get this solved I will also call OS and TP to make sure I am showing ticketed with them.

Oh, and the scary thing, the UA agent yesterday said that when I call back on Monday they will try to work it out with TK, and if unable they will "find a way to get me to LIS". That is not good. I don't want to go direct of via FRA, as they will probably suggest. I have hotel reservations in VIE and PRG. But I understand that my contract with UA is for IST-LIS transportation, so am unsure of how much I can push for the IST-VIE leg.