Is your design public? I can’t print it if the design is not public.
Click on Design>Properties and change the Visibility from Private to Public.
Name your design – change the name to something that makes sense like “Milstead – golf switch 1”.
Move objects closer
1. If you have multiple objects in one design you can increase your printing speed by moving them closer together. Make sure that the objects don’t overlap.
Is your design on the build plate?
1. Check and make sure that your design is sitting ON the build plate in Tinkercad.
2. Drag the black arrow up or down until the distance above the build plate is 0.00mm. See the example.