So then I reread the documentation and it says that "/tmp" should be where you unzipped apex to (for me this is /u01/stage/apex). So Then I tried the command above again with that instead, but received the same error about FILEOPEN failed. That is the only thing that I can think of that could be failing this.The statement that the load image script is trying to run is this:
So make sure that the argument you pass to the script will result in a correct path to the actual location of the unzipped files. So I think in your case the argument should be "/u01/stage" so that the full path will be expanded to "/u01/stage/apex/images" by the script.
create directory APEX_IMAGES as '&1/apex/images';