[2.1.9] Construction bots stuck delivering modules to entity marked for upgrade

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OzoneGrif
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[2.1.9] Construction bots stuck delivering modules to entity marked for upgrade

Post by OzoneGrif »

Issue Description
=============
Personal construction robots get stuck in an infinite loop (hovering and twitching rapidly above the player), trying to deliver modules to an entity that cannot accept them yet. This happens when an upgrade ghost (AM1 -> AM2) and module ghosts are placed simultaneously, but the player only possesses the modules and lacks the upgraded machine.

Cause
=====
Trying to install ghost modules in an assembling machine 1 (AM1).

Steps to Reproduce
===============
- Your character must have a personal robot port with construction robots ready.
- Place an Assembling Machine 1 (AM1) so it is materialized.
- Place an Assembling Machine 2 (AM2) with modules so it is materialized.
- Have modules in your inventory, but not any Assembling Machine 2 (AM2).
- Use the copy tool on the materialized AM2 that contains modules.
- Force-paste this blueprint directly over the built AM1. This creates an upgrade ghost to AM2 along with module ghosts.

If you have an AM2 in your inventory to do the upgrade, it works fine.
But if you do not have an AM2 in your inventory, the robots try to install the modules in the AM1, causing the issue.

Expected Behavior
==============
Robots should not attempt to deliver modules to a machine until the upgrade ghost is fully resolved and the entity has been upgraded to a version that possesses module slots. They should wait in the inventory until the AM2 is built.

Ref.: 134979
Attachments
factorio-current.log
(12.48 KiB) Downloaded 16 times
Solo-Robot bug.zip
(1.78 MiB) Downloaded 18 times
Last edited by OzoneGrif on Tue Jun 30, 2026 11:18 pm, edited 1 time in total.
OzoneGrif
Burner Inserter
Burner Inserter
Posts: 5
Joined: Sun Aug 25, 2019 10:37 pm
Contact:

Re: [2.1.8] Construction bots stuck delivering modules to entity marked for upgrade

Post by OzoneGrif »

Update:

It also happens for roboports. I see robots dance in and out of the robotport when you have missing entities in your logistic network.
Attachments
Screenshot 2026-07-01 003533.png
Screenshot 2026-07-01 003533.png (319.81 KiB) Viewed 227 times
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