**System Information**
Windown 7 Ultimate x64
GTX Titan
**Blender Version**
Broken: 2.69.0 r60995
**Short description of error**
Blender Crashes when changing selection modes when in edit mode of mesh imported from airfoild data base file using third-party addon bpyAirfoil found here: https://github.com/brotherlu/BPyAirfoil
**Exact steps for others to reproduce the error**
The mesh should already be in Edit Mode. Attempt to change selection modes. Blender will stop responding. Blender will also stop responding when performing certain mesh operations, though I have been unable to pin down exactly which those were.
I am also unable to convert these triangles to quads using Alt+J or manually by selecting two triangles and pressing F.
{F78349}
I suspect the issue is less to do with Blender itself, but with the addon and how it imports meshes. However, I felt this may be an issue with Blender's robustness and could potentially use fixing.