When attempting to reinstall Microsoft Office, Error “30015-11 (3221225506)” – an error message appeared when the installation progress reached 94%.
Error Code: 30015-11 (3221225506) – 
Error Code: 30015-11 (3221225506)Troubleshooting steps
This error occurs due to the Office installer not having permission to write to the system registry due to lack of permissions.
To repair registry permissions, download Windows Repair and run it only with the first option checked ( Reset Registry Permissions ).
After running the repair, try installing Office again.
Useful links :
Repair an Office application
Office installers error due to “permission to write to the system registry”
Thanks very much for this, this resolved my issue, kudos!
Thanks enormously for providing a solution to this issue. I spent hours trying to overcome this error and you seem to be the only one who understands it and is capable of fixing it.