Error when running a compiled executable

Thank you. I tried running the file, with the new executable I created, by linking the source_newgen.f file, using the lfluka script:
~/fluka/fluka_work/bin/myfluka -M 5 snre_gcr_source.inp
but I’m getting the error:
STOP NO INPUT FILE
STOP STOP: FLUKA ABORTED
It works with the rfluka executable, so is it potentially an issue with the myfluka executable I have created?

rfluka is the launching script to be (always) used to start a FLUKA run, in this case with your custom myfluka executable. See the running instructions:
/pathtofluka/bin/rfluka -M 5 -e ./myfluka snre_gcr_source.inp
(assuming that you execute the command from the directory hosting myfluka and the input file).
You may want to use Flair, which makes the process much more straightforward.