I read a few posts on this, I had collected all the Motifs from the Anniversary event, I learned probably 40 of them in a short time, now I am getting this error. Its been about 10 minutes, still can't log in... hopefully it will clear.
Hey @IAmBones, Error 307 usually resolves within 15 minutes. This article provides some more information. If the issue persists, please contact Customer Support.