the black popup says "no route to host"
-to me - it seem, to be something on your network side
switch LAN or wifi off and try again
if the error occurs try to ping the address:
behind the black popup window I can see something about an address. is it the one from the remote host ?
It seems that disconnecting the wired option on the Pi and just leaving wifi on fixed it. Not sure why this is, that both can't be on, but all of the artwork downloaded, refreshed, and no errors. I was also able to update add-ons and install them when those wouldn't update either.
Also just an FYI the network behind the window was my IP address and I just erased it. Wasn't anything with the remote host.
I'm not sure why I didn't think to disable the wired network and just leave wireless on, but like I said, I didn't think it would be an issue. Appears it was. Is this something where you can't have both on?