**System Information**
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: NVIDIA Quadro P5200/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 466.11
**Blender Version**
Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-08-03 20:35, hash: `rBfb87d236edb7`
Worked: (newest version of Blender that worked as expected)
Caused by {rB39b2a7bb7e815e051348bf5c5ec777d091324164}
**Short description of error**
Blender crashes in Edit Mode when:
1. The autosmooth checkbox in `Properties > Object Data Properties > Normals > Auto Smooth` is enabled and set exactly to 180º (the deafault 30º value or 179º work and **don't crash** Blender)
2. An operation like inset, bevel, etc is used on a non-manifold mesh (like a plane or any other non-clossed geometry).
**Exact steps to reproduce the error**
1. Default factory settings
2. Make the default cube a non-manifold mesh by deleting any part.
3. Enable auto-smooth (`Object->Data Properties->Normals->Auto smooth) and set the value **exactly** to 180º
4. Select a face and use inset, bevel.... (extrude seems to work but I think is because when you extrude a face you create a volume, so a non-manifold plane mesh becomes a manifold surface with this operation)
Thanks!
Test File:
{F10264488}