APS Installation Issues
I have noticed the following:
If running on a multi-server environment, wherein, a different db server, web server and etc some times APS installation fails ..
A close investigation indicates that, it fails when the web server ISPConfig cron runs before the db server cron ..
So when the web server installs the application and notices the db does not exist yet, it fails and produces an installation error. Always in this case there are no config files.
Therefore, my suggestion would be to check the existence of a db (if required by the application) before installing the files ...or create a slight delay for the app files to allow the db server create the respective app database.