I bought three NUC7i5DNKE Systems, one NUC has always boot with the message "System in Manufacturing Mode".
Even after updating the BIOS to the latest DNKBLi5V.86A.0040.
Reset BIOS to defaults.
Rebooted 20+ times.
Still have the message.
I know this is not an answer, but I would return it.
Maybe N.Scott.Pearson or cvare can help?
Looking into this. Will PM you or reply when I find something out.
If you update to BIOS 0037 or later and turn secure boot on, the message will go away. Otherwise it will go away after 50 boots.
Retrieving data ...