It gets sent and the new user receives the email...but it just stays in PENDING. If you cancel and re-invite there is a message the Intuit's system is having issues and to try again.
UPDATE: I called in to Support today and got it resolved. I was trying to setup a new user to three different accounting firms I work for...so the same user to three different Lacerte accounts. I was successful with getting this user setup to one accounting firm last week but the other two accounting firms I tried to set up this user on during Saturday just wouldn't go through. Support during the near hour call came up with instructions for me to tell the "Primary Admin" to invite the new user (I'm not a primary) and then when we were wrapping up the call I looked at all three accounts and the new user was showing up. So somehow Intuit's system pushed the new user invite through without having to get the "Primary Admin" involved. Problem solved so I moved on...but it was a mystery to Support as to why it went through as is. Who knows!!!