My Mac says that the software is from an unidentified
Mar 13, 2013 3 Ways to Allow Installation of Apps from Anywhere in Apple maintains a level of control over the apps you can install on your devices which protects your Mac from malware and bad user experience. This can be frustrating and worrying if you want to run an app and you are confronted by a warning that it is from an unidentified developer. How to Open Application From Unidentified Developer on Mac Based on this possibility, Apple made a policy that the software that can be installed by default is only the software made by an identified developer, so that we can have trust when installing and using the software. Apple provides a gate for us so we can choose, download and install the application through the Mac App Store safely.
Installing software from an unidentified developer
Installing apps on Mac is easy. All you’ve to do head over to the App Store, search for the app and install it. That’s what Apple recommends. Installing apps from other sources is never easy and will be blocked when tried to install even after downloaded. They are blocked by a specific security feature which is called Gatekeeper. Install Sumac - Sumac Non-profit Software You may see a message saying that Sumac is from an “unidentified developer”. If this is the case, right-click the Sumac icon, and select Open from the menu. Opening it this way allows you to bypass the security block put up by your system. For more information please see the Apple support topic on this issue. Click Open.
"unknown developer" so can't install Office 365 for 2016
If your Mac is set to allow apps from the App Store and identified developers, and you try to install an app that isn’t signed by an identified developer or—in macOS Catalina—notarized by Apple, you also see a warning that the app cannot be opened. Fix: Can't be opened because it is from an unidentified Jul 30, 2018 How to Disable Gatekeeper and Allow Apps From Anywhere in Dec 26, 2019