Not sure if this is your problem, but I have found those "advanced sharing settings" to have changed after a Win 10 update was installed, locking me out from sharing my digital music files. It happened last month with the Fall Creators Update.
I have no password. My setting are Turn on network discovery, Turn on printer and file sharing, Turn off password protected sharing. I also look at my Music folder after an update to make sure that the Properties show the folder as "shared."
This may be superstition, but after I change these settings, I turn off the Oppo player, reboot the PC, then restart the player.
Denon x4400h, Samsung LED 1080p TV, B&W 704 mains, two M&K subwoofers, Oppo 103, Roku 2, Darbeevision, etc.
Headphone system: Focal Clear, Sennheiser HD600, AKG K702, Hifiman HE-400i, Marantz HD-DAC1, Denon DVD-3910