VMware Cloud Director 10.4 was launched almost 3 months ago, if you have an older version is a good time to plan and upgrade to the latest version.

Since versions prior to VMware Cloud Director 10.3 reached the end of support it’s a good time to upgrade to version 10.4.
You can check the Lifecycle Matrix here:
https://lifecycle.vmware.com/#/
Platform Services & Operations improvements
- Enhanced visibility into catalog synchronization steps and progress
- Fast cross-VC catalog instantiation with shared storage
- Service account API tokens
- Consolidated VM console on VCD API URL
- High-priority automated test suites run on CDS
- Support for all VCD workflows through a proxy between VCD and vSphere (including for automated tests)
- Multi-tenancy service account enhancements
- CSE / Container enhancements
- Extensibility enhancements
- Terraform & vRA enhancements
Networking improvements
- Static Routes
- New NSX Advanced Load Balancer Basic Features
- New NSX Advanced Load Balancer licensing model
- Mitigation for NSX-T vApp fencing limitations (API)
Storage improvements
- Better IOPS reporting
- SDRS enhancements to save VM placement time and utilize proper storage space
Compliance updates
- STIG Readiness Guide
- Photon OS 3.0
If your Cloud Director is the appliance version, you can directly migrate from version 9.7 and up.

In the case of a VMware Cloud Director Linux-Based Upgrade with the external database, you can go to version 10.4 from 10.1.4.1
In all of the cases, please check:
- Check the Interoperability guide for software compatibility
- Check the 3rd Party solutions interoperability
- Check the system requirements and installation
- Check the VMware Cloud director extensibility interoperability (Hyper Plugin, CSE, NSX Migration, VRO Plugin, ALP, OSE, vROPs adapters, etc)
- Check the hardware support
- Backup the appliance before the upgrade
- Backup the VCD database before the upgrade
- Take a snapshot of the VCD appliance before the upgrade