Please try this.
Open new project.
Then Import AI file into project
Drop Puppet layer into time line or Scene..or Add to Scene from the button of the panel
Creating and opening scenes
To create a new scene, do either of the following:
• Choose File > New Scene (Cmd/Ctrl+N), type the name for the scene, then press Enter or click away from the text field.
A new empty scene is created in the Project panel. It is not opened, but you can add puppets and other supported
project items to it.
• Select one or more puppets or other supported items in the Project panel, then drag them into an empty Scene or Timeline
panel, click the Add to New Scene button, or choose Object > Add to New Scene (Cmd/Ctrl+/).
A new scene containing the selected project items is created in the Project panel, and is opened in the Scene panel. If
only one item was selected, the new scene is named after it.
The new scene defaults to the same frame rate, duration, width, and height as the last-created scene or the last scene whose
settings you modified.
To duplicate a scene, select it, then choose Edit > Duplicate (Cmd/Ctrl+D).
To view the contents of a scene, double-click the scene item in the Project panel. The scene opens in the Scene panel.
To manually update the scene in the Scene panel, click the Refresh button at the bottom of the Scene panel or doubleclick
the scene in the Project panel. Refreshing a scene is useful if you want to reset simulations (e.g., Dangle or Particles
Certain features in Illustrator (e.g., gradients) are not supported by default in Character Animator. However, you can treat the AI file as a raster image so it will be by selecting a skin layer (with a square icon) in the Puppet panel, then enabling the "Render As Image" option in the Properties panel. That should at least make the rendering the same as in Illustrator.
As for why the scene is blank, there could be some problem with a guide/handle that's not placed correctly. If it's possible to share a copy of the AI file that we can diagnose, that'd be helpful. Thanks.
Mey be re installation will help.
Reinstall shouldn't be necessary.