Items in inventory disappear while moving other items

I don't have the screenshots. But I have had things disappear when moving it from one character to another. I picked up a book from an area with lots of books and it should have been in my inventory so I could sell it to a faction or use it or something. And it is gone. I had a duplicate recipe book go mia as well. I am not sure what else I might have lost over the course of the game so far but those are some of the things I know for certain are mia.

I think what is happening, at least on my end, is that when trying to transfer items being picked up, it is grabbing things from our backpacks instead.  It is annoying, but it's best to just "loot all" then move the items manually you want to give to the character you wish to place said items with.

I have also found that if you have a lot of items, and you don't scroll to the bottom of your inventory before grabbing stuff from containers, that you grab stuff from your backpack instead.

Fix for now: Scroll to the bottom of your inventory before looting.

I have lost several items when attempting to transfer them from one character to another. I lost a wand of lightning bolts and a +1 split mail armor. I reloaded the save and the armor keep vanishing everytime I would give it to my Dwarf Cleric. He was wearing a Handy Haversack. Both characters had pretty full inventories.

This only happens to me when I have enough items in my inventory that a scroll bar appears to the right, the same as the picture of the OP. If I don't have that many items, my items won't disappear.

Same problem for me specially after I scrolled down to access the items. 

Moreover it happens that items change of kind, not of nature (ie stones can change from emerauld to opal, scrolls from wizard shield to jump....).

Hi, same problem here and it is a BIG issue : I've lost many items that way, including quest item (the ghost bones for example) and my thiefs lockpicks...
At this point I prefer to wait before playing again. Hope this kind of bugs will be fixed soon because it clearly ruins the experience, even for an early access.

Same. I just had 2 stacks of emeralds disappear.

I have the same issue was just checking to see if it was a know issue 

I've had quest items disappear because of this bug and break quests, but I've noticed it for all kinds of items. Anything that reduces or adds to the number of rows in an inventory seems to be able to trigger it.

Agreed that this is a distressing bug. Almost makes me want to stop playing until it's fixed, but I know I'll keep going. I'm going to be very anxious every time I'm in the inventory screen though -- which is damned near 1/4 of the playing time because there's no where I can stash stuff. Oh for a safety deposit chest at a bank or inn!

My personal temporary solution is to give a character a lot of items to expand their inventory for multiple extra rows, and then take some items (not from the end) back to other characters, so there are a bunch of half-filled rows and inventory grid is never "full". That way I don't lose items from inventory. You can also rearrange items freely unless you take last item from a row.

I've experienced this as well. There's a lootable armor stand in the Bone Tower that contains +1 half-plate and a +3 shield. I tried on multiple characters but it wasn't possible to loot both with one character: you'd either get the armor or the shield. My work around was looting it twice: one character grabbed the armor, the other grabbed the shield. That and a few other missing item hiccups caused me to start quicksaving before mucking around with inventory. I'm on my third party and this issue is persistent across all of them.

Ditto on this issue. Didn't notice it is an many places as you are all finding it. I only noticed it once when I was selling some items. Accidentally clicked some ingredients that I wanted to keep. When I clicked them to come out of the store they just vanished. 

Still have items disappear even after last patch.