c# - ASP.net Web API Unauthorised Access -

i have set new asp.net mvc , web api application default individual accounts authentication system, , have working regular controllers authorise attribute, when try same web api controller, hit unauthorised access, despite having access initial index page. once logged in , on index page, click button fires off request api, reason receives unauthorised request. missing?

does work:

[authorize] public class homecontroller : controller {     public actionresult index() {         return view();     }  } 

doesn't work:

public class taskscontroller : apicontroller {     [authorize]     [httpget]     public ienumerable<usertask> getalltasks() {          using (var db = new testdb()) {             var tasks = db.usertasks.where(o => o.createdbyuser == user.identity.name).tolist();              return tasks;         }     } } 

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