We have heard some reports of difficulty creating links in an email blast -
To lend clarity, the link would initially create in the WYSIWYG, but then I'd lose changes after hitting save. Not sure if Erwin had the same or a slightly different experience. My problem resolved after about a dozen tries and then giving up and creating an all-new blast email.
This has been fixed.
Please email examples of blasts where you are having this problem to firstname.lastname@example.org.