This is generic problem which is popping up while using RWD UPerform Tool. The only solution for this problem is :
1. First select the step where the simulation actually stops and does not move forward i.e. in your case the step is 29th.
2. Check in the Step Text of that particular step-29. Check if there are gaps in between the text and picture of the action like back button,exit button or data field symbol. If needed add spaces.
3. Then publish the UDC file and check if your problem is resolved.
4. If still the problem exist then re-record that particular step once again after deleting the odd one.
Do post about the recent development on this issue.