Factorio Forums

Attached is a save file of a multiplayer game. However, I was able to recreate it in single player as well. Should the steps below not reproduce it in single player, try starting a dedicated server using the saved game and join that as a client.

1. Load up the save file
2. Below area marked "Iron Smelting" there are some Assembly Machine 3's with Speed Module 3's inside of them.
3. Click on an assembly machine 3 to open it's inventory
4. Pick up a speed module 3 from the assembly machine 3 by clicking on it with the mouse

Result: The speed module 3 is briefly attached to the cursor, before vanishing a few moments later.
Expected: The speed module 3 stays attached to the cursor.

Alternatively:

4. Pick up a speed module 3 by shift-clicking

Result: The speed module 3 is briefly put in your inventory, before vanishing from the inventory a few moments later.
Expected: It is put in your inventory and doesn't vanish into the unknowable void

This happens 100% of the time, even after restarting the server, to everyone connected to the server. It also happens in single-player. The speed modules do not end up in any inventories - they simply vanish completely. If you shift click, it will briefly go into your inventory before being deleted. Speed module 2 and speed module 1 do not appear to be affected. We haven't found any other items that are vanishing when picked up yet. I think that putting a speed module 3 from your inventory into the machine will also make it vanish, but since I can't pick them up anymore I can't test this.

No mods are being used, this is entirely vanilla factorio.

Machine specs:
Windows 10 Pro x64
16 GB RAM
Intel Core i7
Geforce GTX 1070

Not a bug: your construction robots automatically pick them up and deliver them to the assemblers a little bit further down that require the modules (the assemblers with the blue triangle).