My bitnami stack of ResourceSpace was almost perfect but for one thing (well, one thing that I could see) - there were no previews being generated when making a contact sheet.
Looking through posts on this Group, and Google, it seemed to be due to Ghostscript not being installed on the server by default.
I'm pretty green on all things ResourceSpace and Linux generally, but these are the steps I took to install it and it works great now, so is here for your information - if you already know this, please disregard, but I really could have done with it an hour ago ;) .
1. SSH into your bitnami server (I used Terminal on a Mac).
2. Type sudo apt-get install ghostscript (ENTER and wait for it to finish)
3. Type sudo apt-get install libgs-dev (ENTER and wait for it to finish)
4. Type sudo apt-get install gs-esp (ENTER and wait for it to finish)
Exit the Terminal.
Open config.php in /opt/bitnami/apps/resourcespace/htdocs/include
Add the line $ghostscript_path = 'opt/bitnami/common/bin'; and click SAVE
and you should see something like Ghostscript GPL Ghostscript 9.05 (2012-02-08) OK
Try previewing your contact sheet again and, all going well, it should now work.