Get it here or via 'Help > Check for Updates' in 9.0.A1+.
Please ensure you have 'Auto-Save' and 'Backups' enabled in the Preferences
What's changed from 9.0.RC3:
- Fixed translation of 'Word Cloud > Edit Ignore File' dialog
- Fixed keyboard editing of 'Attribute Editor > Date' fields
- Fixed refresh of 'Attribute Editor > Custom Calculation' fields