Welcome to the Candy Crush Saga Community
Do you have a question or need help with your game? Ask the Community.
Hi Jan- What type of device are you using? Make sure that it is compatible with Candy Crush Saga here- http://candycrushsaga.com/help/en
If your levels are backed up on Facebook I would suggest uninstalling the game, restarting the device and then installing the latest version of the game from the app/play store. Please note that this may cause you to lose some of your Boosters.
Let me know how you get on :-)