I'm pretty new to Blender, and I have a model that I am having problems with. I have some non-manifold geometry but I don't know what's wrong. I highlight the edges but I don't see anything wrong with the edges the pointed out. Here is a screenshot:
I've tried deleting the edges, because I thought they might be duplicate, but they're not. I tried deleting the surrounding faces and regenerating the faces manually, but that doesn't help. I created this model with a face I subdivided, then extruded the nine faces. Then I cleaned it up and added a bunch of vertices and faces. I thought maybe that construction technique was bad, so I tried creating this same thing by starting with two cubes and repeatedly boolean subtracting the "carving" cube away from the main form. But after four or so cuts I started getting non manifold errors with this technique as well. Any ideas? If you tell me how to export just this object, I can do that and share it if that would help. Thanks in advance!
Okay, here is the file if anyone wants to look: https://www.dropbox.com/s/2g00zfgs5xyzdhd/non_manifold.blend?dl=0
Inspecting the mesh, I couldn't find the problems you guys mentioned. Maybe I just don't know Blender well enough to see them.
As to Make Manifold, I never saw that button there, LOL. It actually works, which is great. Thanks!
I will still be playing around with the mesh as a learning experience however. I want to figure out what is wrong with it.