That warning pops up automatically if the settings vary in any way from the correct default settings for the material, and it’s designed to keep you from making a mistake. It’s a reminder to check your settings.
If you are using Proofgrade material, and haven’t changed the settings…the possibility is that you are using the wrong settings for that material. Check the thickness of the material, it’s easy to confuse the Thick Maple Ply and Medium Maple ply, and when the machine takes a height reading, if it gets something different from what the settings show for thickness, it’s going to show that warning.
That’s one possibility. Another is that something changed the last time you ran that file and the changes were saved. (Maybe 2 passes or a different LPI.)
First look at the thumbnail column closely. Any time you see a speed/power number in an operation listing instead of just the words Engrave, Score or Cut, then the default setting has changed for that operation. You will see the error message listed on the side for that. (Even if it’s a non-destructive change like lowering the LPI or setting a second pass.)
To change that back to the default, click the Back button for the thumbnail and just choose Engrave Score or Cut at the top. The correct default settings will load, and the error message will go away.