Altium Designer Unknown Pin
You probably have edited the the schematic symbol in Sch library after placing its footprint on the layout design.

In situations like this, you need to update your schematic design from library (Tools/Update From Libraries...), then update your PCB with the updated schematic. If problem still there, remove the footprint from PCB file and update the PCB file with schematic again.

Also make sure the symbol in schematic sheet has the same footprint model name as it has in Schematic and PCB libraries.