Some resellers sell keys for this version as "cheap" Office 2016. These are often illegitimate volume licenses that Microsoft may revoke at any time. Microsoft Learn How to Fix Mondo 2016 Issues
"Mondo" often appears due to a licensing mismatch. If you have a legitimate key for Office 2016 but the software says "Mondo," you may need to clear the current license and re-add your correct one: Open Command Prompt as Administrator. Navigate to the Office folder: cd C:\Program Files\Microsoft Office\Office16 cd C:\Program Files (x86)\Microsoft Office\Office16 Display existing keys: cscript ospp.vbs /dstatus and note the last 5 characters of any active keys. Remove the Mondo license: cscript ospp.vbs /unpkey:XXXXX (replace XXXXX with your noted characters). Restart Office: microsoft office mondo 2016 product key