The Patient Set Viewer and other ACT software requires a working directory. Here the software creates and updates files for background jobs, caching, and other tasks. The software needs create and write access to this working directory.
In the ACT_config.php file, we have provided a default location for your working directory. It is: /opt/viewer_jobs. You can have to provide the correct access by :running the chmod command as shown.
For example, on your DEV server chmod 777
Make sure web (HTTP) access is not allowed to this directory