Altium is killing me! I am basically doing a semi-volunteer project to learn Altium, my previous workplace used Eagle. I made a library from scratch and compiled it to an integrated library. The library compile without any issues, and all of the symbols are associated with a footprint.

When I want to 'compile' from schematic to PCB, some of the parts complain about not being able to find their PINS. Their is also an error about not being able to add components to a class, I didn't create the class and I am not sure what the purpose of it even is.

When I go to the library for the capacitor, Pin 1 is mapped to pad one on the footprint and Pin2 is mapped to PAD2 on the footprint.

Any Ideas?

I am not sure how to embed the pictures bigger, but if you right click them and choose open picture they are bigger.

Thanks! Design>>Update PCB Result

My Main View in Altium

  • \$\begingroup\$ I notice now when viewing the picture that all of the Unkown Pins are either connected to VCC or to GND... Can it be something to do with that? \$\endgroup\$
    – AJBotha
    Apr 29, 2015 at 5:54

1 Answer 1


This has nothing to do with missing PINs in components. This has to do with that the PINs in the schematic differs from the PINs in the layout. My guess is that you have added components to the schematic and when you validate the schematic against the layout (Validate Changes) Altium can't find the new PINs in the layout. A strange way of the program to say that you have added new pins to the schematic that are not in the layout. This happens often for me as well in Altium.

If you press Execute Changes, I'm pretty sure that Altium will add the new PINs to the layout without giving you any trouble. I'm not sure but if you then press Validate Changes you will get nice green circles all the way.

  • \$\begingroup\$ I find that very unintuitive! I just found the solution on another forum dating back to the days of Protel!If I execute, exit and then verify they all come back as AOK. Thank you very much! \$\endgroup\$
    – AJBotha
    Apr 29, 2015 at 6:29
  • \$\begingroup\$ Yes it is. The first time this happened to me I also reacted like you did. Strange way of saying "These newly added PINs to the schematic hasn't been exported to the layout yet." \$\endgroup\$ Apr 29, 2015 at 8:25
  • \$\begingroup\$ Thanks for the response. You got right, the execution works and pins are created on the layout. Is this an altium bug ? Should we report that ? \$\endgroup\$
    – user92621
    Nov 24, 2015 at 13:04
  • \$\begingroup\$ Thanks. But what is the reason of this behavior? I've exactly followed the official DXP tutorial (MultiVibrator) (with the exception of choosing parts from Vault) and it still gives me the error. \$\endgroup\$ Dec 7, 2017 at 12:42

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