(As of March 2021, Viewer is only supported on versions of Microsoft Windows supported by Microsoft. Before March 2021, Viewer ran on Windows, Mac, and Linux. At that time, we dropped support for Mac and Linux due to low demand. This article remains for those running unsupported versions.)
OS X Gatekeeper occasionally shows this message when it does not recognize an installer's digital signature. To run the application for the first time, you will need to disable Gatekeeper as follows:
- Go to System Preferences... | Security & Privacy | General tab.
- Click the Lock icon in the lower left corner and enter your password to make changes.
- Select Allow apps downloaded from: Anywhere.
You can enable Gatekeeper again after the first successful launch of the application.