If the upgrade is stuck when at the downloading packages stage, you may revert to the snapshot and retry the VMware Aria Suite Lifecycle 8.x upgrade.
Note: Proceed only if you do not have backups or a recent snapshot before the last attempted upgrade.
rm /etc/upgradeprogress
For more information and Best Practice guidance on doing an upgrade of vRSLCM, see the VMware vRealize Suite Lifecycle Manager Documentation - Upgrade vRealize Suite Lifecycle Manager 8.x guide.
Related KB:
Troubleshooting VMware Aria Suite Lifecycle 8.x upgrade failures due to missing packages