Have you run across this error?

Errno::EIO at /applications

Input/output error – <STDERR>

• file:lint.rb 
• location:write 
• line: 398

This is what caused it for me. My program has a “puts” statement or something similar that needs to write to the terminal. When I run the program as a daemon, it still continues to write to the terminal. But if I disconnect my laptop that has the terminal open, the terminal session is broken. There is no longer a place for the application to write the output of the “puts”.

Temporarily, just restart the app. For a more permanent solution, remove the puts statements or make them part of an “if DEBUG”.