Dell UltraSharp U2417H User Manual page 45

OSD Warning Messages
When the Dynamic Contrast feature is enabled (in these preset modes: Game or Movie),
manual brightness adjustment is disabled.
When the monitor does not support a particular resolution mode, you can see the
following message:
This means that the monitor cannot synchronize with the signal that it is receiving from
the computer. See Monitor Specifications for the Horizontal and Vertical frequency
ranges addressable by this monitor. Recommended mode is 1920 x 1080.
You can see the following message before the DDC/CI function is disabled:
When the monitor enters the Power Save mode, the following message appears:
Operating the Monitor | 45