Factorio Forums

When replacing more modules in a machine than a bot can carry, the excess are dropped on the floor and not replaced, leaving a machine with missing modules and a mess to clean up.

Expected behavior: Bots should only replace the number of modules they can carry and leave the remainder for another bot to complete.

Post a simple save that shows exactly that happening please, see 3638.

As a potential quick fix for spillover issues like these, see
https://mods.factorio.com/mod/Nanobots

The item retriever module will mark all items on the ground (artifacts, etc) in your personal roboport construction range for deconstruction as long as no enemies are around.

(I will note that some of this logic is already in vanilla, for the spillover from overflowing Cargo landing pad getting auto-deconstructed.)

I created a test world and enabled cheats and researched all tech to get an example to show.

There are two rows of 20 Foundries set up both with different module configurations. The top row contains 1 rare speed 2, 1 rare efficiency 2 and 2 normal efficiency 2, while the bottom row contains 4 rare speed 2.
I then copy the bottom row and paste it over the top to get the robots to update the module configuration of the top row.
I then put the bots in the roboport (had them out to take a screenshot of the commands before they started) and this was the result, with one of the 4 new modules totally missing and one of the old modules on the floor:
The last screenshot just highlights the items on the floor with a filtered deconstruction planner.
This only seems to happen with certain module configurations and I suspect it has something to do with the bots inventory getting overfilled with modules.

As there are empty module slots after the action, the issue might be related to 118943 Module insertion doesn't fill empty slots in module inventory if there's a request after them.

It does seem similar to that issue.

In the example above, the first module slot is the same in both, so only the 2nd to 4th get a request to change and then the 2nd one gets missed and dropped onto the floor instead.

But the strange thing is that is isnt all of them. a different number of machines have the issue each time, even with the same configuration starting and copying. sometimes 19 / 20 drop and sometimes only 16/20 etc, but the issue is repeatable.

In this case, the issue occurs with copy and paste and all 3 expected module swap requests appear, only the first one in slot 2 just gets dropped onto the floor instead of being swapped out.

Video and log file attached.

Expected: all 5 rare modules are placed in the EM assembler, previous modules are taken away to storage.
Experienced: 4 rare modules were inserted, one of the previous modules got dropped on the ground.

Possibly because previous modules were a mix of common and uncommon, so a single bot couldn't carry both types away?

Thanks for the report. I think this is a duplicate of 119524.