Check the line on which Speech Control stopped and make sure that isn't blank. If it is, delete that blank line and save the file. Then run the Speech Control again.
If you are having trouble finding blank lines, go to View > Invisibles. This will display the non-printing formatting marks ("invisibles"). Each time Return or Enter was pressed on the keyboard you will see a backwards P symbol:
Each section of text in your script should end with this formatting mark. If you have any blank lines containing only this mark, delete them. Once the blank lines have been removed from the script, Speech Control should run smoothly.
To hide the formatting marks again, click on View > Invisibles.