Digital Certificates

Digital Certificates are a security measure to protect users from malicious software. The idea is that a company that wants to distribute software buys a "certificate" as proof that the software they produce is legitimate, and not a technique to infest the user's computer with viruses or spyware. The company issuing the certificate investigates the company that is purchasing the certificate, to make sure they are legitimate.
For an in-depth review of the subject, see this discussion in Wikipedia.

Microsoft requires digital certificates for addins to its Microsoft Office products. As an additional precaution, Microsoft restricts the length of time that certificates for its addins can be issued, to a maximum of two years.

Unfortunately, this is a problem for customers who want to continue using their addin software for several years. Also, software may be produced long before it is purchased, but certificates begin to expire from the date the software is developed, not from the purchase date.

As a result, you may at some point encounter a dialog when you run a Microsoft Office product saying that the digital certificate for LEC has expired. We provide a free download of software that will patch your digital certificates so that they remain current in this situation. The software is available here.

You should quit running all Office applications before running this certificate updater.