View source for Uncaught TypeError: Unsupported operand types

@WikiAdmin Uhmm...So it's probably a stupid question. --As I pointed out in my previous comment, I lost all the data from my wiki site, including the database. And I didn't have time to rebuild my site until the last few days. I seem to have had to do an upgrade, but I couldn't because of the lost database tables. Is there any way to allow me to do a re-install rather than a version upgrade?-- 
Updated: I found an old copy of the database files on my local device and I uploaded it to my new database, so the wiki site has been online. However, when I try to save my article after edited, I will get an Error 500 page. How can I debug and fix it?