When modifying an IJS Extruded Profile library item make sure that the extruded shape is the first item in the Main Set assembly.
Never have the Deactivated Coordinate System as the first item.
If the AL Angle is not the first item in the assembly then it produces a fatal error either upon insertion or applying mitre joins.
Why not delete the Deactivated Coordinate System?
We can delete it but this coordinate system is a preventable measure to stop the assembly defaulting automatically to Single Unit mode. We require the breakdown for BOM and a clean display of library names in the tree when inserted into a project.
Will this be reported to Missler as a bug?
No, technically you can’t extrude a coordinate system and if it is the first item it sounds reasonable that it will produce a fatal error.