I think my Traveling sack is invisible. I removed my traveling sack to free one of my hands, after i wille i had to free my other hand...but where is my traveling sack? i searched all my chest and nothing, so i said "i will mine then" i tried to remove my trav sack and...
i tried to empty or fill my inventory and the same thing happend
Go into a chest with free space and shift+scrolldown or Shift+Alt all item into the chest, it should appear in the chest.
Its a glitch where the bag comes off and still registers its own inventory slots, putting the bag within itself (xfiles theme music)
I had this glitch a loooooooooong time ago, and still get it occasionally.
Best way to avoid this glitch is to not Shift+Click the bag off your hands, rather click and drag it over, or simply make sure that your inventory is empty enough to hold the bag.
"The psychological trials of dwellers in the last times will be equal to the physical trials of the martyrs. In order to face these trials we must be living in a different world."