Error message when using Session Manager

Every was ok, then i have this error

VM41:1 Uncaught SyntaxError: Unexpected token u in JSON at position 0
at JSON.parse ()
at sessionManager.js:28
at Array.reduce ()
at n.getData (sessionManager.js:26)
at n.render (sessionManager.js:22)
at n.constructor (BaseComponent.js:20)
at n (appConnect.js:490)
at n.e.hasOwnProperty.e.constructor (appConnect.js:523)
at new n (appConnect.js:490)
at n.$addChild (BaseComponent.js:213)