I am not sure , but this might be associated with a crashed computer. After restarting (after the crash) I get a missing helper error where the helper name is wrong. Switc
This had been bugging me for so long. I didn't find any joy with attempting to rename the files or directories.
I did, however, find a really easy fix. Simply go into the main directory of your project and run 'bundle install'. It installed all of the gem dependencies (without overwriting any data I had written) which effectively fixed any issues.
Opened up the rails server and hurrah, normal service was resumed.
Hope that helps!