Check that your device’s IP address hasn’t changed; if you’re using DHCP, and the device reboots, your router may re-assign the IP address. This can cause problems for networking.
I assume you’re using the DLNA Media Server in the MyCloud to access your media on the TV, rather than a network file server. If so, you need to make sure that the Media Server is running, and that it is looking in the right place for media. Both of these settings can be mangled by firmware upgrades.
I’d also go through the process of connecting your TV to your network; there’s probably a setup required to connect to a file or media server.
And yes, you can revert to earlier firmware versions: search for threads on ‘downgrade’.
