Unfortunately there was an issue with linking in the WYSIWYG
editor in
yesterdays release which we completely missed, so we've fixed
that this morning and
updated the release so we now have an Umbraco 4.0.2.1 aka the
"digit edition".
The update service have been updated to automatically notify
existing Umbraco 4 installations about this update.
Thank you to our wonderful community who found this error and
reported it quickly and sorry for any inconvenience.