That sounds like Gatekeeper. To disable it you need to follow the instructions at the link Jim gave above.
To bypass this problem and install Panorama 6 on a new macOS Sierra computer, you must disable the Gatekeeper feature. To do this, start by opening Terminal.app (in the /Applications/Utilities folder). Then type in the following command:
sudo spctl --master-disable
You'll be asked for your computer's administrator password. Once you've entered it, Gatekeeper will be disabled and you can run the Panorama 6 installer.
After Panorama 6 is installed, you can turn Gatekeeper back on if you want. To do that, again use Terminal.app but with this command:
sudo spctl --master-enable