Kerbal Space Program

KSP version: 0.24.2.559 vanilla 64-bit on Linux

• Go to VAB, start a new craft, and place any root part
• In symmetry mode 2 or greater, place a part with 2 attachment nodes that can be surface-attached (like a modular girder. Works in any orientation)
• Still in symmetry mode and without rotating the part, try to attach any part with an attachment node to an exposed node

• Debug console spams "[Exception]: NullReferenceException: Object reference not set to instance of an object"
• Attachment nodes of held part become fixed while mouse is positioned over node on craft
• Held part is displayed in symmetry, floating in the air about an arbitrary center position (see below)
• The part can't be attached

With some parts, like the claw and the Rockomax 48-7S, after hovering a held part over a node on the craft, the part can't be dropped in the empty space in the editor; occasionally, these parts can't be attached until they are snapped to (by hovering near) a non-symmetry attachment node.

Note: I recall identical behavior (the frozen nodes and weird symmetry for held part) with some of the same parts as far back as 0.21 on Windows.