The Unreal game engine is continually updated along with the editor. Bearing this in mind, the documentation is not always updated before the new version is released.
To add on to what has become a frustrating situation for me, Epic allows users to use any version of the engine licensed to them during their subscription period. This means that each version will have a different feature set and a particular documentation that will be most relevant to that particular version.
This being said I’d like to suggest two features
Feature #1: Versioned documentation
This would simply ensure that a copy of the manual and reference for UE4 can be downloaded for the version fo UE4 that the developer wants to use.
Feature #2: “This page is valid for version X for Unreal Engine 4”
For those viewing the online only documentation, I’d like to see the pages stamped with a version identifier so that I and other users can know which version of the engine, the page is most relevant to.
A byproduct of this stamp would allow the documentation team to quickly find any page that’s not updated for the latest version and verify the content. If any changes need to be made they can be made without long periods of time being spent cross-referencing content.