Printing objects are inside bleed
This check ensures that all objects that are set to print are on the page or within the bleed area. Any printing objects that are completely outside the bleed area are flagged.
The ‘pasteboard’ is an area is outside of the InDesign page which can still be used to hold objects whilst working on page layouts.
When files are ready to output, having objects hanging around on the pasteboard, can cause problems and confusion. Also it means the file is larger and more complex than it needs to be. Extra image links, swatches and fonts might be used, word counts and text extraction could be affected.
However, in some cases notes or other objects may need to be retained for future users. In this case objects can be set to non-printing in the InDesign Attributes panel (Window menu > Attributes panel)
Another way to set objects to non-printing is to make their layer non printing. Select the layer in the InDesign Layers Panel (Window menu > Layers) and double click the layer name to see the Layer Options dialog. Make sure the layer is visible and uncheck the Print Layer
This check looks at the position of the objects that are not set to non-printing (either on a non-printing layer or set to non-print in attributes panel) and checking that all items are wholly or partially on the spread or within the bleed area. Objects that are only on the pasteboard and outside of the bleed area are flagged.
Fix this problem by setting objects to non-printing, moving objects within the bleed area or deleting them. A GreenLight tool is available to remove all pasteboard objects at once (GreenLight menu command Tools > Print Tools panel > Delete pasteboard objects)
Adobe InDesign help on setting bleed
