After a teamfight, unable to cast spells until I died and respawned

[aaak84]

I was playing Geist. After a teamfight, I was unable to cast any spells. I had a lock symbol around me that wouldn't go away. It did go away after I died and respawned. I don't know the exact time in the replay (replay not ready for download yet) but it's during the last 10 minutes or so.

Match ID 288295