Missed the box and now stuck

I have a specific player I am using for my projects and it is classic, which I am not updating until all the projects in my current group are completed. When I went to publish my latest project WITH the classic player, the box asking to use modern must have popped up. I didn't click anything sooooo it must have assumed "yes". When I previewed the project the modern player was active. NOW when I am trying to go back to the classic player I use in the .story file it tells me "To restore compatibility with the classic player, remove the dialog layer or change it to a standard layer."

 

Can someone tell me how to find that layer? Or can I do it under the Design tab for all of the layers? Is it going to "blow up" everything I've done?

Not a little frustrated here! Any help greatly appreciated!!!