Generally, you can safely ignore this type of error message when important files. If you receive an error like this, check the models to make sure that they imported into your scene successfully and look good.
If you do not see the models in your scene, keep in mind that our models are built at 1:1 scale. Depending on your 3D software you may need to adjust the camera clipping in the viewport or scale the scene to match your software's settings (for example Maya uses 1/10 scale by default).
You can also check your outliner to see if models did successfully import into your scene.