I have the same error
Warning: Smarty error: unable to read template resource: "styles/mozilla/tiki.tpl" in /var/www/html/tiki-1.7/Smarty/Smarty.class.php on line 999
it is not easily apparant how to fix. I selected the theme logged in as an admin, so I see nothing in tiki_user_preferences I did try the technic listed here: https://sourceforge.net/tracker/index.php?func=detail&aid=782608&group_id=64258&atid=506846 and that didnt work for me. Going to try renamimg a theme again. very strange way to error. Is there no way to trap and revert?
sigh! I do love Tiki though (love hate kinda thing)