1. Previews currently are only supported on non-windows systems
2. LibreOffice/OpenOffice needs to be installed
Ubuntu/Debian -> apt-get install –no-install-recommends libreoffice-writer
CentOS -> http://diegolamonica.info/how-to-make-l … entos-6-3/
3. The correct path to your libreoffice / openoffice binary needs to be configured (check the manual of your system how to find it)
4. Make sure that the user running your webserver/PHP process is allowed to execute this binary
5. The PHP functions shell_exec() and escapeshellarg() are needed for the preview generation so make sure that they are not blocked in your PHP configuration (Hint: disable_functions)
6. Check that you have configured your PHP directive open_basedir correctly to allow the access to the path which was configured in 2.)
7. Check that you have configured SELinux correctly to allow the access to the path which was configured in 2.)
8. Finally check that you don’t have configured an empty “preview_office_cl_parameters” option in your config.php and remove it completely as it is not really needed in a default environment.
9. If this is still not working check your logfiles as described in viewtopic.php?f=17&t=7330
