What is new icon on PLAY button?

Am running the latest version of iStopMotion for Mac, and I’m perplexed by this new icon that appears on the PLAY button. Everytime I click the PLAY button, Preview plays only about four frames, then stops. I can’t watch my whole project. Anyone know what’s up with this? Thanks much.

I had this problem too, it’s sooooo annoying. My Dad found the solution after a few minutes: go to the top menu called movie and make sure play selection only is not selected. Alternatively, you can toggle this by pressing S on the keyboard. The play button should return to normal. Hope this helped, good luck with your project :smile: