For the most part, TeamViewer is able to make connections without any special configuration of a device. However, it is possible that your TeamViewer (Classic) may indicate a red light and the message Not ready. Please check your connection. 

This article applies to all TeamViewer (Classic) users.

Here are a few things you can check if you experience this alert:

Did your general setup change?

  • Is your internet connection working? Try to load a webpage or other web-based application.

Did anything change on your IT setup?

  • Can TeamViewer (Classic) reach the internet?
    • If not, please open Port 5938 for outgoing connections

📄 Ports used by TeamViewer - TeamViewer Support

General This article applies to all users in all licenses. TeamViewer is designed to connect easily to remote computers without any special firewall configurations being necessary. In the vast majority of cases, TeamViewer will always work if surfing on the internet is possible. TeamViewer makes outbound connections to the…

 

Did TeamViewer (Classic) work just a few minutes ago?

  • Exit TeamViewer (Classic) or reboot the device
    • On Windows: Go to the hamburger menuExit TeamViewer
    • On Mac: Go to TeamViewer Quit TeamViewer
  • Did you check our Status page?
    • All updates about the current status of all TeamViewer Services can be found here

🚨 TeamViewer Status

Welcome to TeamViewer's home for real-time and historical data on system performance.