Using the Eurail planning app in Vienna, Austria is pretty problematic. Vienna has at least three separate stations if not more. When you attempt to find a train from Vienna to Salzburg for example, it just shows Vienna until you click it and then you see which station - which is sorta inconvenient but workable. Keep in mind it might take 30 minutes to get from one station to another via undergrounds, so its vital to get this right.
But it gets worse. Sometimes it shows Wien Meidling as station and sometimes not when looking for Vienna. But we found that there actually was a train leaving from there, which did not appear in the app. Finally found it by looking specifically for Meidling Wien. I have no idea how many other valid trains are not appearing.