I just downloaded and installed the engine for the first (4.10) time and grabbed some marketplace content to evaluate. Hovering over the “i”, it tells me which iterations of the engine it’s compatible with so I reverted to 4.8.3. Unfortunately, I’m still getting a message that says the content isn’t compatible.
Yeah. Unfortunately the marketplace content has to be updated by the original authors. Epic put in place some stipulations that say it has to happen within x amount of time, but it doesn’t seem like it always does with some. Sadly, all you can do is downgrade to a lower version of the engine, import the content, then try to either export it or migrate it to your newer version of the engine. Most of the time it works.
I find it very hard to believe that they can respond to all of the emails that quickly, it even takes me many days to get a response after just asking a simple question 
Hey BringMeASunkist,
I moved your thread to the Marketplace section, I think it’s a better place to discuss this issues 
This white window shows you that everything is ok, if it incompatible then you will get “Not compatible with Unreal Engine 4.10”(Which is absent on your screenshot) so just click Create/Add to project and everything should be fine.
Also, most of the Marketplace projects(Not all though) are compatible even with higher version, but they are not yet tested and marked as 4.10 so if you want to take a risk or test project in 4.10 environment you press Add to project and check “Show all projects” and choose project you want to add this pack to.
Thanks a lot zeOrb. Looks like I didn’t have any projects created so the content couldn’t be added. Still figuring out the directory structures with UE4