The information in this article applies to:
* Version 5 of Nitro PDF Professional
Symptoms
The following error message is displayed when starting Microsoft Word, Excel or PowerPoint.
A certificate (signing or issuer) has expired.
Cause
Digital certificate used to sign the Nitro PDF add-ins (to identify the publisher as Nitro PDF) has expired.
Resolution
1. Please remove your currently installed version of Nitro PDF Professional from your machine:
XP users: Control Panel > Add/Remove Programs
Vista users: Control Panel > Programs & Features
2. Download the updated installer for Nitro PDF Professional 5, (which contains a new valid certificate) via the relevant links below:
Nitro PDF Professional version 5 - 32-bit
http://www.nitropdf.com/professional/builds/nitro_pdf_professional5.exe
Nitro PDF Professional version 5 - 64-bit
http://www.nitropdf.com/professional/builds/nitro_pdf_professional5_64.exe
Products 