As Simon says this usually means that the name of the reference from the component type (the Java interface or BPEL partner links for example) does not match the name of the reference found in the composite file. So first thing to check is that the string "warehousePartnerLink" is the same in the composite file as it appear in the component implementation.
Judging by the name of the reference this looks like a BPEL process is used to implement a component. Again, a look at the composite would be useful. Regards Simon
