Hi there, `org-drill' has broken recently (after git commit "3380460"), here is the steps to reproduce the issue:
1. Create a new org-mode buffer with the following contents: * org-drill test :drill: Foo ** Answer Bar 2. M-x org-drill 3. Press <SPACE> 4. Press `2' and you are stuck there forever until pressing `q' or "C-g". Thanks, York