[Pod]

Originally Posted by imiviortal

latex directory is right.

Not only the directory, but the path to the executable.

Also, remember that this is the path in the file system of your server, not your home computer.

Originally Posted by imiviortal

where can i find the "error file"

Depends on your hosting. If you have cpanel, you can probably see it there.

Originally Posted by imiviortal

in addition, what is the :

Document class
Class of the temporal latex file. The compiler should have access to the corresponding .cls file.

where can i see where is the .cls file ?

You don't need the full path here, just the name of the class. You are probably safe leaving the default value (article).