According to TribLive,
"...the full band version of the song was met with much applause, before being dampened with a misspelled 'Thank You Pittsburg' sign that came down at show’s end. It was obviously unfortunate, but even more so because Taggart made it a point to talk about how great the city had been to The Chainsmokers and not every city was as enthusiastic as Pittsburgh."
The band made a joke on Twitter:
“lol totally putting our visual guy on blast for misspelling Pittsburgh at the end,” they wrote on Sunday.
However, the tweet is now deleted.