Hi there!
I was hoping someone could offer a helping hand. I keep getting the same LOD errors:
My LOD group consists of 3 objects named f.e. Cake_LOD0, Cake_LOD1 and Cake_LOD2. Everything is working as it should, but I always get these errors no matter what I do. My solution has been to just ignore the warnings, but I would love to get rid of them.
Thanks!
Hey, did you ever figure the error out? I’m getting the same error
Unfortunately, nope. 
I’m just ignoring it for now.
Could you solve the problem? My asset package works fine in new version, but I need to work with lower version for some other errors! But the old version 5.3.4 keeps giving me this error!!!
I may have found the solution.
Unity wants the LOD objects to be sub-objects parented inside a root object. For me working out of Blender, this means rather than exporting my fbx files as separate objects, I select all the objects that are part of the LOD group, and export all as a single fbx object. Inside Unity, the hierarchy will show each sub-object (with names taken from the blend file) as children of a root (named during export). This gets rid of the error and also organizes my assets more efficiently. I’m assuming this is the general solution regardless of file-type or 3d editor.
Good luck!
Edit:
Interesting note: dragging a model organized this way into your scene will cause Unity to automatically set up an LOD group and apply the appropriate LOD’s. This is insanely convenient and exactly why we got the error; it’s trying to build an LOD system for you on import but needs an empty game object as the root. Or something to that effect, my terminology is sometimes a little off :P. But yea this is the way to go.
