Just by virtue of the "Access is denied" part, indicates that something within your OS/driver setup/something - is blocking you. Just a matter of finding out what it is. I would recommend resetting your printer' settings (hopefully it has the capability), so you have a clean slate to work from (no old settings getting in your way). I'm not very familiar with the "Shareport" function of the router so can't comment on that, but keep in mind that NO COMPUTER/or device on the computer can do anything without instructions/programming of some sort from software/device driver(s)....etc. In other words, that router function is governed by some instructions as well, so if it were me, I'd check into that too.
Hope it helps.