Since Ready or Not is a multiplayer game, you have the ability to play with your friends... as long as the game actually lets you. If you are unable to, I will explain how to fix this below.
How to fix Ready or Not multiplayer issues
If you cannot join your friends, or vice versa, there can be several reasons for this. So, the best way to resolve this error is to troubleshoot each possible solution while restarting and attempting to join the game. Below are a couple of fixes you can try:
- Ensure the internet works on each side.
- Restart your PC.
- Check the Ready or Not on X, Reddit, and Discord to see if there are any server outages.
- Check for updates and ensure all parties have the latest version of the game.
- Remove any mods on each side and try again.
- Check if Steam is not facing any outages.
- Make sure your Firewall is not blocking any connections.
- Ensure all Windows updates are installed.
- Verify the integrity of all game files via properties in your game library.
Related: Ready or Not Patch Notes
It is important to try to join friends in between each of these troubleshooting steps. If it still does not work, I highly recommend contacting the game's support and informing them about the error, along with the steps you have taken to try to fix it.
For more on Ready or Not, be sure to check out Ready or Not – How to get S rank and Ready or Not DirectX 11 or 12 – Which one to use? here on Pro Game Guides.