This seems like a timing issue. You might need to wait a little bit between each of the steps. Without getting hands-on, my initial test would be to add a 10 second pause between each step to confirm that it is indeed simply a timing issue. You can then gradually reduce the pauses, or investigate other possible events that you can wait on to inform you when the next step is ready to be executed. Ideally, you'd locate some other event or value that changes that you can detect as pauses are not always guaranteed to be long enough (perhaps the application is having a slow performing day and your 1 second pause that works most of the time, now suddenly does not).