I ran rake assets:precompile by mistake on development, and Rails stopped loading the assets on development. I only get application.js and ap
Incase it's helpful to anyone - I had an issue where neither application.js/.css loading in development (I could still see the manifest lines when viewing the source).
I was running an old rails 3.2.2 app for some reason I had to go in and add blank line to both the manifest files (application.js & application.css) and save them - then assets started working properly.
I removed the blank lines and it still worked so I'm assuming perhaps it just needed a newer modified date stamp on the files.