Vessels near runway vanishing

[adalast]

I am trying to build a mini mining and refinery next to the runway to make some money in career mode and I keep having ships vanish. I just tried to put my Sky Crane out there while I load in the next piece and when I return to the space center, the ship has vanished. This is getting really annoying as I have also lost several very expensive base pieces trying to do this as well. None of my other ships are being lost, just the ones near the Runway. I haven't tried to put any anywhere else around the VAB, so I don't know if it is local to the runway or Kerbin

Here is my sfs file

https://www.dropbox.com/s/9ehmrqj02os5qu8/persistent.sfs?dl=0

[magico13]

Are the vessels moved off of the runway completely? If not, they'll be recovered when you launch a new craft. You have to move them so they're not on the sloped grass, all the way off to the "normal" terrain.

[adalast]

i figured that much out. they are all the way off the slope, about 300m away.

[adalast]

No other suggestions?