Troubleshooting - 01 - failed to load external entity

Error Message: 

Fatal Error: DOMDocument::load() [domdocument.load]: I/O warning : failed to load external entity (# 256)

Error Stage:

Development

Error Location: 

include.xml.php5.inc

Error Detail: 

File to be loaded was not correct.
getXSLfile was not giving out the file name properly (one node in file path was missing)

Error Fix: 

Check file name.

Error Fix2: 

None.