Brushes, Swatches, & Presets
Why it appears: You've made a selection and used Edit>Define Brush Preset, but the wrong layer (without any pixels in the selected area) is active.
How to fix it: Make sure the correct layer is active in the Layers palette before attempting to create a brush preset.
Why it appears: You've made a selection and used Edit>Define Pattern, but the wrong layer (without any pixels in the selected area) is active.
How to fix it: Make sure the correct layer is active in the Layers palette before you attempt to create a pattern preset.
Why it appears: When you use the flyout menu in the Brushes palette (which is nested in the Palette Well) to load a set of brushes, you can replace the current brushes or add new brushes to the existing set.
How to fix it: Not a fix, but a decision: replace the existing brushes with the new set (click OK) or add the new brushes into the existing set (Append). (If you replace the brushes, you can always reset the brushes back to the default set by choosing Reset Brushes from the palette's flyout menu.) Note: You'll get the same warning dialog when you want to load a new set of swatches, shapes, gradients, patterns, tool presets, styles, and contours.
Why it appears: You chose the Replace Swatches option from the Swatches palette's flyout menu (Window>Swatches). If you have previously changed the Swatches palette (added or deleted swatches), you'll get this warning.
How to fix it: You have a decision to make: save the swatches that you have previously edited; click Don't Save and continue replacing the swatches; or click Cancel to leave the swatches unchanged.