This is not a helpful message.
Not only is it very cryptic it provides no help towards a solution nor any suggestion about what bad things are going to happen (or not) if I ignore the message.
But there is a bigger issue. References are being updated continually. As a competent designer, I know this. Raising this message as a pop-up notification causes a level of alarm which is unwarranted. Logging this message in message center ONLY is sufficient. Then in the message center provide verbose instruction on what is generating the message and how to correct it.
In my case, this is most likely being generated because the 3D cut in my profile is indeed out of date. I purposely avoid updating it for very longer periods because the command is so darn slow. So, the message should just say that the 3D cut is out of date, so I can determine whether I should call 911 or go on my merry way.
In a world where any particular model may have dozens of attached references the following would be examples of more appropriate messages: