The game is stuck at 100% on the installing screen.

Double tap anywhere on the screen to open the "Are you sure you want to return to the main menu? You will not lose your progress." window.
Select "Yes" and you will be returned to the Main Menu of the game.
Load the game again to have the "Installing" screen appear again and this should resume the download again without issue.

If you are still having an issue, please email support at supportdos2@larian.com