Updated Lakka, now I'm missing cores and menu options

I updated Lakka using the lakka-update tool to the most current build (Lakka (unofficial) Version: devel-20160511225718-r21438-g88de891). I’m unable to update through the XMB menus since it just continually tries to download over and over and never completes. Once I updated, I lost the update cores menu item and I don’t seem to have some cores that are listed in the /storage/cores directory. An example of a missing core is the Atari Jaguar core. Yes, I know that core isn’t great and has issues, I’m just using it as an example of one of the many cores that are missing. Likewise, in the /tmp/cores directory there are a bunch of .info files with no corresponding .so files.

How can I get the update cores menu back and how can I fix or add the missing cores?

Core updated has been removed because it can cause issue. You have core depend on your platform, if a core is not there yet, it means it doesn’t work on your platform. But you can still open an issue to confirm it.