First I suggest that you update the firmware of AC RYAN, which you can find here
I own a AC RYAN HD 2 years now and every update gives something more every time.
I have had several problems with SAMBA every time I update Ubuntu.
Make sure that the samba packages are ok and the 2 sabma services are up and running. Go to the software center and and type system-config-samba package. If you dont have it, I suggest you donwload it.
Remember that for samba, workgroup is important, so make sure you work on the same workgroup in the AC RYAN and as do for the rest of the network. Through system-config-samba you ; ll be able to set it.
Check that the samba services are up
If everything fails then you can always use ftp to transfer files with AC RYAN.
sudo ps -C smbd
sudo ps -C nmbd