Ok, that’s not the curdled appearance that I was talking about. I would suspect lumps in the sugar, particularly if it were brown sugar. I would also suspect undermixing of the shortening and flour. Are you using an electric mixer?
I used brown sugar and a standing electric mixer.
I added the shortening and butter together to the dry ingredients. After mixing the butter, shortening and dry ingredients, the mixture looked like cornmeal with some big lumps. Should I continue to mix until there are no big lumps? Will there be a danger of over mixing?