hi 3dpg im trying to add a threaded through-hole to this duck. i basically boolean'd some models i found online together in blender, and picrelated is what i got. But when I import this geometry into bambustudio, it says my geometry is fucked up (it complains there are 'non manifold edges')

Is that because my geometry is nonsensical (the threaded hole is just a boolean; there's no "inside" of the duck with thickness or anything) or is there something I can do to trivially fix this? In my head I feel like the slicer shouldn't care if the inside of the model doesn't make sense and can model slice by slice if it just does an intersection with outer facing edges