Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hi,
Are you using Windows or macOS?
If you are using a Mac, which version of macOS are you using (for example, Ventura 13, Monterey 12, Sonoma 14, or Sequoia 15)?
Are your Microsoft Office apps updated to the latest version?
In the meantime, you can check and try the solution provided by Microsoft for the 0x0 error here: https://support.microsoft.com/support/known-issues/unknown-error-0x0-license-not-found-error-microsoft365-macos