How to Troubleshoot Invalid Certificate Error in Office Mac 2011?

Microsoft Office for Mac 2011 is a version of the MS Office productivity suite for Mac OS X. The system specifications required to install this Office suite is 64-bit Intel processor and OS X Yosemite or later. The Office suite supports exciting enterprise support and greater feature parity with the Windows edition. Office 2011 supports online collaboration tools including OneDrive and Office Web Applications allowing Mac users to edit the document over web. While installing Microsoft Office for Mac 2011, you may encounter an error and the most common one is “Invalid Certificate” error. This occurs at the time of installation. Before we move ahead to the troubleshooting steps, one must check out the reason behind this:

Cause

It occurs when a few of your installed and update packages are signed up with the older certificate.

To troubleshoot or fix this error, you simply need to download a package of newer version that includes an updated certificate to use for your installation. Don’t worry; this error will not affect your license or Office subscription.

1. Once you see the error message “The package was signed with an invalid certificate. This package might not install what you expect. Do you want to continue with the installation anyway?“ prompted in a dialogue box, click Cancel
2. Download the package with the latest version using the below given link:

• Office 2011 Volume License packages (build 14.4.3) that were downloaded from the Microsoft Volume Licensing Service Center (VLSC) prior to March 8, 2017 (all languages)

LINK- https://www.microsoft.com/Licensing/servicecenter/default.aspx

• Office 2011 14.7.1 Installer for Italian and Norwegian

LINK- https://www.microsoft.com/en-us/software-download/office

• Office 2011 14.7.1 Combo update for German, Japanese, and Polish

LINK- https://support.microsoft.com/en-us/help/3198809/ms17-014-description-of-the-security-update-for-office-for-mac-2011-14

• Lync 14.4.1 installer

LINK- https://support.microsoft.com/en-us/help/3175174/july-2016-update-for-lync-for-mac-2011-14-4-1-kb3175174

1. Now, open the update from your Downloads folder
2. Click install to begin the installation process
3. You are good to go!

If you still face trouble in the installation, contact Microsoft Office.com/setup support team and get the error fixed by a certified technician. They will be glad to assist you!

Source: http://office.com-setupinstall.com/troubleshoot-invalid-certificate-error-office-mac-2011/