First, let's make sure that you have not just accidentally logged in as a Guest. If you usually play via Facebook, please go into the game settings and re-connect. 

If this is not the case and you have always been playing as a Guest, crashes or new updates can cause loss of game data. If you still know your former support key, please include it in message to us at https://jamcity.helpshift.com/hc/en/64-ninja-turtles-legends/

If you do not remember your former support key, please send us your current one and we will do our best to help you out.