Is it just me or does it seem like Marketplace Items take forever to be updated for new engines. For instance, A lot of the good foliage packages on the marketplace can’t be used in 4.9 yet. It took forever for the 3dfoinpackage to be updated for use in 4.8 and they just released a 2nd version and it’s only usable on 4.9. What needs to be done in order to get them available for the new updated engines?
I’m guessing all they need to do is convert the projects over and make sure they work with the new engine. I personally seem to be having issues lately with my blueprints after converting, but I think that the reason most are so slow to update is as simple as them not getting around to it. Yey 1500th post 
Got a link for you with Jon Jones answer to that (:
https://forums.unrealengine/showthread.php?82691-4-9-Compatibility
Thanks!! It’s nice to know the process!
During the time that you wait you could also just add the content into a 4.8 project and then just update it to 4.9 -> now you can use it in 4.9 projects (but it could be that some stuff, especially blueprints, breaks -> but with materials, meshes,…you shouldnt get any problems) 
Last time I tried that, some of the animations wouldn’t work and I kept getting crashes. I’ll give it a try though.