"PLEASE POWER OFF" locked screen

[gingerbread]

After some use a white box appears on the monitor "PLEASE POWER OFF".

There is no further instruction and the mouse does not have any effect. To break out of this situation I have to remove 240VAC from the NVR.
Video recorder = NVR-108MH-C/8P.

Any advice of what may be causing this, and possible solutions?

 

[JB1970]

After some use a white box appears on the monitor "PLEASE POWER OFF".

There is no further instruction and the mouse does not have any effect. To break out of this situation I have to remove 240VAC from the NVR.
Video recorder = NVR-108MH-C/8P.

Any advice of what may be causing this, and possible solutions?

Maybe locate and install the latest firmware if you can. I've not used that model 'but usually 'please power off' appears after the recorder has been sent a shutdown command from the local menu. When doing a shutdown from the local menu, the NVR stops recording (that can be seen by the red clapperboard icons disappearing from the upper right corner of each image) and then that message is displayed.