I made my first fall pumpkin the other day and it looked great, but the fondant was not up to my standard. I did shift the sugar prior to adding it to the MM and wanted to know how to avoid this in the future? I also wanted to find out if others are having the same issue? Usually MMF works for me.
Are you adding your powdered sugar slowly and mixing in before adding more? If you are adding it all at once, this may be the problem. HTH!