I was getting this on both PCs here, and looks like I resolved it. At least for now.
It seems to be related to WMP network so ..
I left the Homegroup on both PCs.
Re-created it and re-joined on both.
Then, in Network and sharing options in Control panel:
Chose troubleshoot problems, and Homegroup.
Ignored the test for network and let it continue with Home Network.
It applied fixes to the Home Network. (certificate refresh) and asked if fixed, I said yes.
Done this on both PCs and the error is gone.