I tried Repair.
Uninstall reinstall.
Updating to Win10 Latest.
and SFC /scannow.
Not fixed.- Contacted Corel support & was told 2019 no longer supported. Its only 5 yrs old!
However on further investigation (trial and error) I have discovered the fix -
Navigate to C:\Users\yourusername\AppData\Roaming\Corel\CorelDRAW Home & Student Suite 2019\PPHome\Workspace
and delete Brushes.ini (or rename it)
Restart Photo Paint.
As someone who has used CorelDraw etc for more than 25yrs I find Corel's response very lacking.