"Package can not be opened because it is from an unidentified developer" problem

Mac Mt. Lion and Maverick being extra picky

Mac OS-X 10.8.x Mountain Lion and 10.9.x Maverick: Please note. Apple now requires software developers to have Apple approved digital signatures for automatic installation on Mountain Lion OS-X 10.8.x and Maverick 10.9.x Cadalog, Inc. does has Apple approved digital signature. However, the Apple gateway often does not recognize Cadalog's certificates for some unexplained reason.

However, all Cadalog's plug-ins can be installed safely and securely for Mac OS-X 10.8.x and above. Please read below to for installation on if you are getting this "Package can not be opened because it is from an unidentified developer" message.

After downloading and unzipping the .zip file, you will see an .pkg installation file. Normally you will double click on the .pkg file from your Download folder to initiate the install. However, Mac OS-X 10.8.x and above, you will get a similar message as below (for any version of SketchUp):

To bypass this restriction, right click on the .pkg file and Open the Installer. See the below image for an example:

When you open the installer, you will see a message like this:

Select open and the installation will begin.

There is some information about the issue of Unidentified Developer programs and how to avoid this message on your Mt. Lion or Maverick system here.