Apple music library unavailable

Recently I've been receiving a lot of errors in Itunes - "There was a temporary problem completing your request. An unknown error occured (-50)" and also error 18003 and -3253.

My music library is unavailable, all songs are grayed out.

This was like this for a week, also had problems connecting my account, then it came back for a few days, now unavailable again.

This happens only on my PC. Itunes on my Iphone works perfectly.

Tried reinstalling Itunes - didn't work.

Is this familiar to anyone?

I work with Windows 10 version 1903, Itunes version 12.10.9.3

Thanks...