Did you setup your NAS with a fixed IP or does it get its IP from the DHCP server in the router?
There are ways to see what the IP address of the NAS is, the simplest, if you have an android tablet or phone is to download netscan from the store. When you run it it will give you a list of all the IP addresses it finds on the local network (the NAS will usually have 'D-Link Corporation' under the IP address.
Just in case there has been a power blip and the NAS has reverted to the default IP address you can also try 192.168.0.32.
Other than that you need to physically check the network connections and also be at your computer and check that you can access the shared folders by copying to and from them. 'Seeing' them via remote access may be an artefact left in the cache of whatever you are using for remote access.
EDIT: I should have said that you need to run netscan while you are physically at the local network.