I had the same issue just now.
I got a similar error message when deleting my instance. Then I clicked on the DELETE button once again, and it was successfully deleted.
Then, I when I tried to create a new instance, the system did not allowed me, with errors (i forgot what the error was, but it has something todo with https...).
But then I tried to create it once again, and it was successfully created.
Now I have my new instance.
Regards,
Tjarliman