Howdy, if possible, post the macro itself so we can take a look at it and see what might be going wrong. As one of the moderators likes to say, "If we're not testing we're guessing, and guessing often wastes people's valuable time". 
If you need help on how to post the macro, just let us know and we can walk you through it.
If you haven’t had the opportunity to read this tutorial, I highly recommend it. It will help you get the most help for your question.
Tip: How Do I Get The Best Answer in the Shortest Time?
That being said: you could try using a Pause until button exists action as seen in the screenshot below. Like @DanThomas said, the button might not be enabled quick enough for the Press Button action to work properly.
-Chris