I have entered the example: www.wolfram.com/mathematica/new-in-10/pdes-and-finite-elements/solve-a-wave-equation-in-2d.html
into 12.0, and gotten an error message in the uifWave assignment. It says, "incomplete expression; more input is needed". I have hand entered the statement from the web since I don't know how to get a copy from the screen--but I believe that I have done it accurately.
Has anyone made this example work? If so, I must have made some error--and would appreciate learning how to copy the text from the screen properly. Otherwise, could someone clarify how to make the example work?