When digging through the; WD Support site, the multi bay My Cloud support sites, and multi bay My Cloud related to P2P apps, the aMule program was one of the links that came up with respect to P2P programs. So I posted it.
Look as a fellow My Cloud user I’m just throwing out options and suggestions because you likely won’t get any suggestions from WD. This is mostly a user to user support forum, it is not often WD staff provide help for anything beyond the basic issues. Your post sat here for 5 days now with no other responses from others including no response WD. A similar post elsewhere asking about the loss of P2P had others indicated using Transmission.
When that suggestion was made, you state that you don’t want a 3rd party application. Other suggestions for other P2P programs are likewise made you again state you don’t want to use those options either. If you refuse to use a third party app to replace a feature in OS3 that WD removed from OS5, then your options apparently are rather limited. Live with OS5 and no P2P app. Downgrade to OS3. Or buy a different NAS device or build your own. Shrugs.
In any event, good luck with what ever you decide to do.