can't get key value from cookies though it was exist but invalid format

Question

I am setting some key in $cookieStore like $cookieStore.put('temp',temp); and saved ok in cookies but some where some bites of key value are changed ,

so when $cookieStore.get('temp'); I get this error :

Uncaught SyntaxError: Unexpected end of JSON input

at Object.parse (<anonymous>)
at Object.vc [as fromJson] (1.4.9_angular.min.js:15)
at Object.getObject (1.4.9_angular-cookies.min.js:12)
at Object.get (1.4.9_angular-cookies.min.js:13)

Please I need to know which can change the format of the value that cause the error when trying to get key value!