since it is working on one site, but not on another, it doesn't have anything to do with the order of install.
Do you have an .htacess file in your site? With the original Poster of this thread we discovered the .htaccess file was causing the issue.
one thing to try is:
in the webassist/kfm/index.php page
find the following line:
and change it to:
if you are still having issues, I can start an incident where we can investigate the problem further.