I will repost from a thread I commented on a while ago:

1. Restart router/modem
2. Open Command Prompt (windows search > type cmd > right click and "Run as administrator")
3. In cmd type:
ipconfig /flushdns > and click enter
ipconfig /release > click enter again
ipconfig /renew > wait a while, then...
4. Restart PC

Since I did that, I can play without annoying 90002 disconnections 2 days in a row now. I hope it will help you as well.