Hi there - if you let me know how many Infinity Tokens and Gems you had I can help. In future please use the manual export or cloud save (cloud save is better as it'll just auto-save for you). There are several reasons your save game can get wiped out on your local machine ... things like registry cleaners or just bad luck on a computer crash etc.
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 "Holyday City"){kind=icon}
 "Tap Tap Infinity"){kind=icon}
 "Sands of the Coliseum"){kind=icon}
If you lost your save file send us a bug report, we can help :)