An error in your system configuration has been detected
General installation instructions can be found
here.
For more specific hints on the existing issues please have a look at the messages below. 
It looks like the directory for temporary files is not writable by the webserver. Please change the permissions of /data/demo.collectiveaccess.org/pawtucket/app/tmp and enable the user which runs the webserver to write this directory.
It looks like the cache directory is not writable by the webserver. Please change the permissions of /data/demo.collectiveaccess.org/pawtucket/app/tmp/ca_demoCache and enable the user which runs the webserver to write this directory.
It looks like the directory for HTML filtering caches is not writable by the webserver. Please change the permissions of /data/demo.collectiveaccess.org/pawtucket/vendor/ezyang/htmlpurifier/library/HTMLPurifier/DefinitionCache/Serializer and enable the user which runs the webserver to write this directory.