Corrupt workspaces may lead to problems with the stability and/or operability of the application and in some circumstances can prevent the application from launching. To restore default settings in Painter Line of Products, do the following:
To reset the user settings to the factory default, do the following:
1. Hold down the Shift key while starting the application.
A prompt will appear asking you to confirm that you want to restore the default settings.
2. Click Yes/Current Workspace. Please note that your customized user settings will be lost as a result.
Note: This will erase all modifications including brushes, papers, textures and other customizations.
Corel Technical Support 
This Worked ! Thank You
LikeLike
Completed reset to my Painter 2016 as instructed and underpainting options are now working correctly and was able to keep my customized brushes and settings without losing anything so far.
Thank You for your help!
LikeLike