The basic thing I do is start over on the setup. Since it's over WiFi you must be in control of all firewalls. Start with these disabled in router and Windows.
I have a LG 43"Smart TV 43LJ 550Z. It is linked via Wifi to my Toshiba laptop, and until two days ago, allowed me to view recorded shows, movies, & music on the TV. I also was able to view items on a thumb drive placed into the TV's USB port. Now all I get, once I get into the folders, is the message :"no photo files or folders exist in storage device," regardless of the input source. I cannot find a solution online. Thanks for any assistance.