Please take a look at Pro/ENGINEER, Creo Elements, Creo Parametric modeling prerequisites for use with Capital and for your situation, especially the last four bullets.
The Creo plugin does not support the network routing method where wires can be routed to individual cavities. In other words, the network segment must terminate on a csys that is designated as an entry port. Consequently, the upstream steps to set up a single csys for all wires terminating on a given connector are described in the four steps above and will help deal with error 3 in your report.
You can always delete existing wires from your harness .prt. They evidently have been created earlier, perhaps manually.