Unable to load Multiplayer configuration. (500) ?

Hello. I’m trying to add multiplayer services to the project, but keep getting: Unable to load Multiplayer configuration. (500)
In the project - service - multiplayer continuous blue stripe (loading) and the inscription: Please go to this link to configure the multiplayer settings. I pass on the link and get the error above. Already I tried to create a new project and the same. Please tell me how to fix it?

did you ever get a fix? @Spacewalker