Summary:
Root nodes doesn't have a ComponentDescriptor that can be looked up via this mechanism, and we probably shouldn't be animating Root nodes anyway (?). This is a debug-only assert but could be causing issues in production.
The fix is simple - just don't animate any changes to a root node.
Changelog: [Internal]
Reviewed By: Nick177
Differential Revision: D28856396
fbshipit-source-id: 43fa0aa723b03b031fee22e0563eb63cc86239b3