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Check to make sure your internet is working on the Mac you're trying to install on. You can do this by opening your internet browser and going to www.microsoft.com. If the page loads, your internet connection is working
Reset your license files
Open Spotlight by selecting the magnifying glass at the top right of your desktop
Search for and open Keychain
Type in Office and then delete the data license file
Try from Safe Mode
Uninstall Office for Mac, and then try reinstalling and activating again
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