Why is most of the stuff in the marketplace not compatible with unreal engine 4.9?

Hey guys, I just got a mail that someone said my both assets are not compatible with 4.9

Why exactly did this get changed ? My packages contain textures only, its literally impossible that anything is wrong with them. Also for 4.9 ? I dont want to resubmit all my things for no reason, if it were 5.0 or so I would understand but this sounds like this will happen
again in the future.

Also I have no clue how I would update my packets, there is no client, no guidelines , no package settings or draft anything I know of, how would I do that ?
We really need Unity-style package drafts, it would make this a lot more bearable.