Hi, EDIT (update): I figured out that the game objects are still there, but the PBMeshes on the corrupted objects are now 0-vert/0-tri - so I guess they were deleted from this bug, not the game objects themselves. Keep that in mind when reading below. I'm not sure where to report this, but recently we moved our project over from the Standard Renderer to HDRP by exporting the entire scene as a package, and importing into a brand new package. After doing this, ProBuilder in the new HDRP project went crazy, giving a ton of errors (so many we couldn't really resolve them), so we uninstalled the package (ProBuilder). Eventually we needed to add more to the level/scene, so we reinstalled ProBuilder from the Package Manager. As soon as I deleted a game object with a PBMesh attached to it, the entire project became corrupted, with multiple other game objects missing (seemingly deleted?). I checked the entire scene hierarchy and they objects are not there nor visible. What's odd is some of the deleted game objects were not copies of the deleted game object, or share same material, etc. All were PBMesh/pro builder created objects though. Some of the materials also became corrupted (reset the shaders, properties, etc.). We were also unable to undo this issue, as the project could not undo these changes (they weren't recognized as undoable I guess in the project undo/redo history). This is a very serious problem for us and has set us back several days. Does anyone know about this or can someone at Unity look into this please? One thing to note is, after the "deletion/corruption," all of the PBMesh game objects with the same name are gone, except for "Cube" So for example, if there were say 2 copies of a game object "Cube(2)", now there is only one and the other is deleted from the project. Using Unity 2019.3.f1 and the latest ProBuilder package as of this writing. Thanks.