Post processing NX operations in certain .prt files returns an error that the software could not open the output file and names the path for the folder of the current setup.
The .prt files are being stored in an archived folder structure that includes special characters as separators in the folder names. In this case, the folder name was using a format similar to:
customer; job; part
Special characters are not allowed in most NX functions. In this case, the software was able to open the file, but post processing could not resolve these folder names as being valid locations. The solution is to rename the folders to remove any special characters.