If you get this error message please try the following. Studio Artist Preferences > General > Change Undo Store from Disk to Memory
Basics of the Dual Paint Mode, Concepts and How to Create Your Own Dual Paint Presets For More Information on Dual Paint please see this DUAL PAINT POST For More Information DUAL PAINT POST
How to Erase the Canvas To erase the canvas choose the Eraser Icon at the top of the Interface or choose Canvas > Erase to See this Post for more detailed information on the canvas eraser options.
Everything You Need to Know about Studio Artist Presets and Preset Management
Resizing the Canvas Please see this tip on Resizing the Canvas And how to Resize the Canvas for High-Resolution Print