Check the following requirements:
 

1. From the Apple menu, click [System Preferences] - [Security & Privacy].
   
   
    
2. Make sure that [App Store and identified developers] under [Allow apps downloaded from:] is selected.
   If it is not, select it after clicking [Click the lock to make changes.]
   If you select the [App Store] option, the installer may not work properly.
   
   
   
   


3. Retry downloading and installing the file.