[0.15.16] Conveyor belt won't move some items

[imajor]

I noticed that there are two military science packs just floating above a conveyor belt, I don't know how they got into this state. Video: https://www.youtube.com/watch?v=fJ54edttj10
If I check show-collision-rectangles then these items have the red box around them. I can also pick them up by hitting 'F'. I can post the save if that helps.

[Distelzombie]

They are lying on the floor for some reason. Did you destroy some belts there at some point?

[imajor]

No, I didn't touch this part for a long time, last time I visited this these items were not there.

[Loewchen]

Post the save please.

[imajor]

I'm trying to attach it here ...

[kovarex]

Thanks for the bug report and save, but to be honest, I have no idea how it happened. As long as I don't have a way to reproduce it, I will have to let it go.
I'm moving it to pending.

[imajor]

I understand. This is not a serious issue, so I guess it is not important to fix. I can imagine it is hard to do anything with it without repro steps. I will keep thinking what special I did, and I will post any additional info (if I can find).