Alpha 5, whenever the last item in a stack leaves my inventory, some of my other items in the inventory disappears(they are still registered, there is just no way to see them or use them in ANY way), and it only reaprears again if I get a full inventory.
What also happens because of this is that my inventory gets all messed up, as an example, my bricks disappears thanks to this bug, and I pick up a new brick, I get a whole new stack of bricks, if I have gotten my inventory back, this new stack is the one prioratized if I want to pick up more bricks. Also, the stack of bricks that came back with the rest of my inventory is connected to the other stack. If I hold the bricks that has disappeared and reappeared, and try to throw it, it will throw the new stacks bricks, if that stack of bricks becomes empty and I pick up a brick again, everything is fixed, as if nothing happened, except for the fact that ANOTHER part of my inventory disappear since I threw out all bricks. This "works" with all items except for the tools(I think).
I hope you understood what I meant and hope it gets fixed in the next patch, since I can't play the game until it's fixed.