Factorio Forums

What happened and in what context:
When holding down the Ctrl + Left Click shortcut to sweep-loot across a row of furnaces, the item collection loop randomly and inconsistently terminates mid-drag, requiring the player to completely release the click and restart the sweep.

Describe the problem by answering these questions
What did you do?
I held down Ctrl + Left Click and swept my cursor across rows of automated Stone Furnaces containing processed Iron Plates to empty them into my inventory.

What happened?
The looting loop inconsistently breaks mid-swipe. Once the lockout occurs, the game completely stops collecting iron plates from any subsequent furnaces I drag my cursor over, even though I am holding the left mouse button and ctrl down and am well within interaction distance. The loop remains dead until I lift my finger completely off the mouse click and start a fresh drag sequence.

What did you expect to happen instead?
I expected the continuous Ctrl + Left Click sweep gesture to reliably and continuously loot every single furnace my cursor touches without randomly breaking the action thread.

Does it happen always, once, or sometimes?
It happens sometimes. While it doesn't trigger on every single pass, it is highly noticeable and frequently reproducible during normal, fast gameplay when moving the cursor across smelting lines.

If you can reproduce the issue, provide the exact steps:
Setup lines of Stone Furnaces actively processing Iron Plates.

Hold Ctrl + Left Click and execute fast mouse sweeps back and forth across the lines to harvest the plates.

Observe that the collection thread will randomly terminate mid-sweep, leaving plates in the remaining furnaces until the click is cycled.

Provide Attachments
Video Link: https://youtu.be/bOSRMqpBgtY

Log-file:

Thanks for the report however I am not able to reproduce any such issue no matter how many times I try.

Do you know of any reliable way to reproduce it? Additionally I have no idea when in the videe you've linked I should be paying attention (I can't tell when you've re-clicked, if you're still clicking, or you let off the button, if the computer thinks you've let off the button even if you physically haven't).

I am holding ctrl the entire time. Every time it stops collecting I am holding ctrl and left click. I am resetting outside the furnace area.

I really struggle to reproduce a condition that does it consistently.

I tried so many different things. For a moment I thought it happened when I mouse outside the furnace.

I started noticing the behavior during a new play through. And it was really bugging me that the collection just stopped (newer had this behavior before), first I was thought I was out of reach, but it seems to be that the filter suddenly no longer allows iron.

So I tried to reproduce. I could pretty consistently reproduce it. But the exact circumstances I could not figure out. I might take 2-3 min of just quickly collecting before it suddenly stopps collecting and I need to reset.

At 48s I am holding ctrl plus left click I am holding continuously until 1:08 and reset I continue to hold until I reset at 1:20. I start holding at 1:48 I keep holding til 2:08 when I reset.

Hey Rseding,

Please disregard this bug report!

It was bothering me that the behavior was so inconsistent, so I did some deeper troubleshooting tonight with an on-screen key-press tracker overlay.

It turns out this isn't a Factorio bug at all—the game engine is processing inputs exactly as intended. Under rapid sweeping gestures, my mouse hardware/driver is completely dropping the Left Mouse Button (LMB) press signal entirely, despite the button being physically held down. Factorio is just correctly registering that sudden input loss and ending the loop.

I uploaded a short follow-up video showing the diagnostic overlay dropping the press completely mid-sweep here: https://youtu.be/jfUjScsZUGw

Sorry for the false alarm, and thank you for taking a look at it!