After Selecting the Import Model Button, You must click and drag out a box and release on the layout screen to represent the imported model location.
Then select the local .xmodel file with the File Select Window
The imported model will be the same model type it was exported as. If the .xmodel file contains a custom Model, the imported model will also be a custom model.
After Selecting the Download Model button, You must click and drag out a box and release on the layout screen to represent the downloaded model location.
The Model Dialog will appear where you can select the desired model you would like to insert.
Click Insert and Model will be added to your layout.