In addition to the procedures described in Q/A section, you need to put a file, called "NM.version" to run number subdirectory in order to explore NONMEM results in fit4NM 3.3.8.

 

You can open and edit this file in editor program.

 

For NONMEM 7

"x"
"1" "NM7"

 

For NONMEM 6

"x"
"1" "NM6"

 

If you used NONMEM 6, you don't have to follow this process, because fit4NM is working well with NONMEM 6.