Unresponsive LMS

Started a few days ago (it not the first time it happens, but this time it is super irritating so I've decided to try to investigate the problem properly) my LMS system become totally unresponsive. Playback of a track (local, remote does not matter) will most often not start or take 30s to start and the service log file is full of sequences like that

[17-02-17 22:09:35.1524] Slim::Networking::Discovery::Players::_players_err or (146) Unable to get players: Timed out waiting for data
[17-02-17 22:09:35.1530] Slim::Networking::Discovery::Players::_players_err or (146) Unable to get players: Timed out waiting for data
[17-02-17 22:09:36.0829] Slim::Networking::Discovery::Players::_players_err or (146) Unable to get players: Timed out waiting for data
[17-02-17 22:09:36.0837] Slim::Networking::Discovery::Players::_players_err or (146) Unable to get players: Timed out waiting for data
[17-02-17 22:09:36.0842] Slim::Networking::Discovery::Players::_players_err or (146) Unable to get players: Timed out waiting for data
[17-02-17 22:09:36.0850] Slim::Networking::Discovery::Players::_players_err or (146) Unable to get players: Timed out waiting for data
[17-02-17 22:09:36.0855] Slim::Networking::Discovery::Players::_players_err or (146) Unable to get players: Timed out waiting for data
[17-02-17 22:09:36.0860] Slim::Networking::Discovery::Players::_players_err or (146) Unable to get players: Timed out waiting for data
[17-02-17 22:09:36.0865] Slim::Networking::Discovery::Players::_players_err or (146) Unable to get players: Timed out waiting for data

I know it sounds like a network issue, but my network works perfectly fine. I have many devices, I can stream netflix, download at fast speed, copy large files from various computer all good, not sudden pause of connection. This is LMS 7.7.5 on Win7. I did not change anything in my network config and again, it works absolutely fine,whether I copy files, stream HD video or do video conf, wired or wireless.

Any idea?

Thanks