Summery: You may have noticed an error message that is displayed when downloading Tableau products using Mac computers indicating that "The installation failed. The Installer encountered an error that caused the installation to fail. Contact the software manufacturer for assistance.” This is due to a change that Apple made on February 14th of this year to its certificate signing algorithm.
Workaround: For any previous versions of Tableau Desktop the workaround to fix this issue is to download the renewed certificate directly on the applicable Mac computer.
The certificate can be found at: Error "The installation failed." Installing FLEXnet on a Mac | Tableau Software
Resolution: The issue can be fixed by upgrading to the following Tableau Server versions:
Tableau Desktop 9.0.13
Tableau Desktop 9.1.7
Tableau Desktop 9.2.5