I had the Bevels effects displayed and one selected. I clicked the trash can and clicked "Yes" in response to the "Are you sure that you want to delete "Scalloped Edge"? That removed it from the Bevels available in the Effects menu. How may it be added back to the Bevels list?
Fortunately, I discovered that if I select a shape tool, the deleted effect is still listed in the Styles list in the Option bar.
Fortunately, I discovered that if I select a shape tool, the deleted effect is still listed in the Styles list in the Option bar.