Error when loading physics clips stored in save

[StrawWagen]

I loaded a save of physics clips in a peer-to-peer session and got this error.

[Proper Clipping] lua/autorun/proper_clipping.lua:227: attempt to perform arithmetic on local 'norm' (a nil value)
1. ClipPhysics - lua/autorun/proper_clipping.lua:227
2. AddClip - lua/autorun/server/proper_clipping.lua:62
3. unknown - lua/autorun/server/proper_clipping.lua:338

Has happened lots now, it only happens in peer-to-peer sessions, local server sessions, but never in real singleplayer.
Could be caused by these props not having an owner, or creator, I don't know if that's accurate though.

Thanks in advance!