How do I solve this error with character rigs?

I'm trying to turn a player into a scarecrow. I found help on the internet and was told to use a plugin called "RigEdit Lite" to rig a scarecrow. I did that, but when I tried to open it with the animation editor, it said "Studio.AnimationClipEditor.RigErrors.MultipleParents". I haven't found any info on this error message whatsoever on the internet, except for one forum post recommending I delete it and start again. I used my pre-made scarecrow model again and rigged it up again, but got the same message. Does anyone know how to fix this?