When designing a circuit, I modified the SCH. After updating it to the PCB, multiple duplicate footprints appeared with the same position number. The update did not delete or merge them. What is the reason?
I think it is due to the first checkbox you ticked. You probably never need that ticked, there are only some very special edge cases for when you want that.
I tested it, and it didn’t work。
Did you try this ?
Removing footprint fields does not remove unused footprints. And the Delete footprints with no symbols checkbox is on.
So I am a bit puzzled why this Error: Multiple footprints found for … occurs.
I do agree with Mineotopia. the Re-link footprints to schematic symbols based … option should always be off, and only be used in some specific but rare scenario’s.
…a little bit of testing later…
Locked footprints are not removed, but they do show up in the Update PCB from Schematic dialog:
(Screenshot from KiCad V8.0.9, so slightly different options).
But I don’t see the Locked Item Shadow. This could be turned off. Are there errors for Cannot remove unused footprints in the update dialog?
A quick fix would be to just delete all footprints on the PCB and then do a clean Update PCB from Schematic [F8], but that would not explain how this happened in the first place.
Ah Yes . . . “Delete footprints with no symbols” is what I had in mind, but it’s already selected as you said.
You can find more information about linkage between footprints and symbols here: Update PCB from Schematic's match methods - #2 by eelik. But I can’t see right away what’s your situation, so the technical explanation isn’t necessarily very helpful for you, either.
Can you share the project in its current state?