ℹ
info HP
Status OSD Lockout
Primary OSD cannot be entered. Function buttons still available.
? What Causes This
Lockout feature enabled by holding the bottom menu button for ten seconds.
ⓘ What This Means
Hold the bottom menu button down for 10 seconds to unlock it.
Source: page 69 of the official manual
From the manual
This error code appears in:
HP Z27 27 Inch 4K Uhd Display