Why does this dependency error happen on Linux but not windows?

In my Node.js code, I receive the following error when running on Linux, but not on my window machines. I don't change the file structure between the two. Why is this occurring?

Error: Cannot find module './app/helpers/textHelper.js'
   at Function.Module._resolveFilename (module.js:470:15)
    at Function.Module._load (module.js:418:25)
    at Module.require (module.js:498:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (/home/bdu/work/srid_tool/server.js:3:17)
    at Module._compile (module.js:571:32)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:488:32)
    at tryModuleLoad (module.js:447:12)
at Function.Module._load (module.js:439:3)”

via Chris Chevalier