Get it here or via 'Help > Check for Updates'.
Please ensure you have 'Auto-Save' and 'Backups' enabled in the Preferences
What's changed from 8.3.5:
- Fixed handling of 'Return' key in 'Time periods' preferences
- Fixed erroneous edit after 'Custom Date' selection in 'Week Planner'
- Fixed 'Markdown' comments code page issue