Get it here or via 'Help > Check for Updates' in 9.0.DP1+.
Please ensure you have 'Auto-Save' and 'Backups' enabled in the Preferences
What's changed from 9.1.DP3:
- Added label background colouring to 'Attribute Editor'
- Modified 'Task Attribute' droplists to group 'Custom Attributes' separately
- Improved consistency of 'Custom Attribute' calculations