Servers become unavailable during maintenances. If that is the case, you should be able to connect to the game at a later time when the maintenance is completed. You can find information about planned maintenances on the For Honor Forum.
If your attempts to connect later are unsuccessful and you get the same error, the cause for the error is probably a time out. In that case we recommend that you try to improve your connection to the game servers. Please have a look at our connectivity FAQs for PC, PS4 or Xbox One.
If the issue persists after troubleshooting on your side, please feel free to contact us!
If you are looking for more information on error codes in For Honor, please check our list of error codes.