It seems that your network configuration prevents Grammarly from working on your computer.
Antivirus software, firewalls, and network proxy settings can cause the issue. Please try to resolve it by turning them off (click here for more details on this). We encourage you to get in touch with your network administrator and ask them to enable a specific web socket port.
Your network administrator can check out the following article on how to troubleshoot the issue:
WebSockets Support Q&A for System Administrators
If that doesn't work for you, please try to log in to Grammarly from another location (office, home, Internet café, or using 3G/4G modem) where the Internet provider is different.