The sentence is fine. To "look into" an issue is to investigate it.
Student or Learner
He is looking into this application issue.
How we say a person is starting to check the issue in the sentence above?
Not a teacher.
If he hasn't started yet, you could say: "He'll look intothis application issue." but if he's doing the investigation now, then the sentence is fine.
Last edited by Rover_KE; 20-May-2014 at 07:50. Reason: Adding 'Not a teacher'.