Hi,
This is not an error message, it is just implying that the actual Drill Drawing will be seen when you output the PCB via either PDF, Print or Print Preview, Gerber, ODB++ etc. The Drill Legend is a Table that defines all the hole sizes in the PCB with a number of different symbols or characters and is shown in the above outputs when a .Legend string is placed on the Drill Layer of the PCB. More information can be found at the following link - **broken link removed** or at the Altium Designer forums - **broken link removed**
Hope this helps!
Best regards,
Neal Jerath
Altium Limited