Please ensure you are on strong, reliable wifi. Take a screenshot of where you are stuck and close the game without quitting completely. Reopen the game. If you are still unable to advance, then close and quit the game completely. You may lose your progress.
If you have quit the game and returned to the same location and are still unable to advance, please submit a ticket using the floating orange Support button. The button appears as "Support" on desktop and a question mark on mobile (example below).
Please include your user name and level, and describe your situation, your device, operating system, and a screenshot if possible.