Using Point&Click UI or the old one? Anyhow your order is perfectly legal, and the error is not complaining about a supposed illegality, it's a technical issue

Is the coast right?

Thanks, I am able to get into the game now, but I have another issue.
I'm England (so I'm pretty much dead in the water now), but when I try to have my fleet in Barents support F GoB into St. Petersburg, I keep getting this message:
Unknown error saving orders, server indicated that API call was invalid

Is that an illegal order? And if so, why?

Thanks for letting me know.. weird because it looks like a normal game. Will debug it asap

Are you suffering from the white screen of death? It can be fixed by entering your orders with the old drop down interface. You can access the old interface by going to your settings and changing your default to the drop down. Good luck!

https://webdiplomacy.net/beta/?gameID=568569
I see that I have orders to input, but when I click on the game, it won't open.