I'm getting this error, but I don't know what it means or how to fix it. Please help :(

[MotokoKHammond]

Error in script 150B5065 (fnSexoutGetSkeleton) in mod Sexout.esm
Failed to resolve string return result (string ID was 1)
Script line approximation: Let skeleton := ##actor.NX_GetSkeletonPath## (error wrapped in ##'s)
        Where skeleton="", actor=[id: FF004FDE, edid: "", name: ""]
    File: Sexout.esm Offset: 0x0097 Command: Let