I have created what I think is a white watermark (by clicking the white square on the left instead of the black square when typing the text). Then I have gone to create it into a brush so I can apply whereever I would like. However now it is saying and I quote
Could not complete the Define Brush Preset command because the selected area is empty.
What is going on? Have I made the watermark white incorrectly and if so how do I go about creating it correctly or do I need to do someone so it recognises there is a watermark?