It may play in Premiere but does it play in AE?
Try opening the footage by itself by double-clicking it in the project window. If it doesn’t play there then something is screwy with the footage. If that’s the case, then check out the interpret footage dialog by selecting the footage in the project window and hitting ctl+F (cmd+f for mac). Check the duration and see if everything else looks correct.
If the footage does play when you double-click it in the project window then something is screwy with the composition that you are trying to use the footage in. If that’s the case, then check the composition settings by opening the composition and hitting ctl+k (cmd+k for mac). Check the duration of the comp and the frame rate, etc.
-E