Set Featured Image and Post Tags not saving

I recently migrated a WordPress install from a subdirectory to the root. After the migration everything worked great, except that I can no longer set a featured thumbnail and I can only set post tags from the Quick Edit screen and not the post edit screen.

When I click set featured image on the post edit screen it opens the screen to add media, but it opens in a new page, not like in a box before. When I click to the media library and click show next to an image, it does not show and so I can’t select “use as featured image.”

I’m not sure if the tags issue is related, but whenever I enter a tag in the Post Tag box it will not save. But if I go out to the All Posts listing, I can enter them via Quick Edit.

Any ideas? Thanks in advance.