A couple of things. First, this is an MMO, so I may need to ask you to contact the game's dedicated support staff at some point if I can't troubleshoot the basic browser issues. Secondly, I need some more info from you all. Can you share some information with us? For example, what OS, browser/browser version are you connecting with? Do you have a screen capture of the error? Does this happen when you load the game with Edge/IE or another browser that supports the Unity Player?
The Forge of Gods support team can be reached by clicking on the gear icon -> click on the support button if you wanted to follow up with them directly.