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Symptoms
Office 2016 For Mac Key Already Used
If you try to activate a one-time install of Office for Mac and you get the error: Key already used, you will need to select another license to use. Click Cancel and you'll return to the license selection screen. The license that you tried to use will be grayed out. You can select any other license that hasn't been used. 8 Things Microsoft Office 2016 is Great for as a Productivity Suite; Message error: '.the specified Product key has already been activated the Maximum number of times' Online activation did not work - the product key used maximum number of times permitted message; How to Change Product Key in Office 2010 Without Uninstalling. If you see the error This product key has already been used when you enter your product key on www.office.com/setup or Microsoft365.com/setup, this means your product key has already been redeemed and is no longer needed. Instead, use your Microsoft account to sign in to account.microsoft.com and install your Office product. This is common if you're using earlier versions of Office (2016 and earlier), Office Home & Business, Home & Student, or Professional. If you have a subscription for Microsoft 365, see Using a Microsoft 365 Subscription on a PC or Mac. As of the release of Office 2016, your product key is tied to your Microsoft account.
In Microsoft Outlook 2016 for Mac, you are repeatedly prompted for authentication while you're connected to your Office 365 account.
Cause
This issue occurs because of the presence of duplicate tokens in the keychain.
Resolution
To resolve this issue in Outlook 2016 for Mac, install the February 2017 Outlook update (version 15.31.0) from the following Office website:
Workaround
To work around this issue, delete any cached passwords for your account, and also delete any modern authentication tokens from the keychain. To do this, follow these steps.
Note
These steps affect all Office applications that use modern authentication.
Key Already Used Office 2016 For Mac
Quit Outlook and all other Office applications.
Start Keychain Access by using one of the following methods:
- Select the Finder application, click Utilities on the Go menu, and then double-click Keychain Access.
- In Spotlight Search, type Keychain Access, and then double-click Keychain Access in the search results.
In the search field in Keychain Access, enter Exchange.
In the search results, select each item to view the Account that's listed at the top, and then press Delete. Repeat this step to delete all items for your Exchange account.
In the search field, enter adal.
Select all items whose type is MicrosoftOffice15_2_Data:ADAL:<GUID>, and then press Delete.
In the search field, enter office.
Select the items that are named Microsoft Office Identities Cache 2 and Microsoft Office Identities Settings 2, and then press Delete.
Quit Keychain Access.
Note
When you start Outlook, you are prompted to authenticate.