iPhone 6s iOS 10.0.2 Calendar won't sync

Hi,

HTTP response code 403

403 in this case means "not authorized" which has some common reasons:

  • You have used wrong credentials
  • You have special chars (umlauts) in your password which is not supported by WebDAV
  • You're using the wrong URL
  • Your webserver is broken

We have a FAQ for such issues (especially the last point is described there) available here: