Starting in Rock v19, unregistered legacy WebForms blocks are now only automatically registered during Rock startup. They will no longer register dynamically when accessing blocks:
- PageZoneBlocksEditor
- ZoneBlock
- MobilePageDetail
This change helps speed up the load time for those pages.
If you have any legacy WebForms blocks that were added outside of a standard plugin install process, they may not be registered automatically. However, as an administrator, you can register any unrecognized blocks manually by clicking the Clear Cache button in the System Information window.