Smart links disappear whenever the Nav Mesh regenerates while using Dynamic Runtime Generation. For example, if you have a dynamic object that is constantly moving and causing the Nav Mesh to rebuild, the Smart Link will be removed from the scene.
Found in 4.11 Preview 6. Reproduced in Main CL 2877267
This does not seem occur in 4.10.4. This is a regression.
1. Open the editor
2. Go to Edit->Project Settings->Navigation Mesh
3. Set Runtime Generation to Dynamic
4. Add a Nav Mesh Bounds Volume to the scene
5. Add a Nav Link Proxy to the Scene
6. Select the Nav Link Proxy, and set Smart Link is Relevant to True
7. Turn on Navigation Visualization ("P" Key)
8. Add a Sphere Object
9. Set the sphere's Simulate Physics to true
Result: Any time the Nav Mesh is regenerated (when the sphere hits the ground or moves), the Smart Link disappears.
Expected: The Smart Link would only disappear when the Sphere was blocking its path.
Head over to the existing Questions & Answers thread and let us know what's up.