You can also choose Paper Select under Details from the Job Status and manually force it from the tray you would like it to print from. However, please note that forcing this could cause the document to print incorrectly since it was not formatted for the selected paper size and/or type.
Typically, if your copier is telling you to “Load Paper” it is because there is a job in the queue requiring a paper size or type that the machine does not currently have. You can go into the job queue by pressing Job Status, delete the job, and resend it with the correct paper size. Confirm the paper size and type from your computer under the Paper tab in your printing preferences.