The search index could not be updated. The site is misconfigured. Contact an administrator. SQLSTATE[42000]: Syntax error or access violation: 1064 unknown table 'tiki_main_67970848c9392' in delete request
Seems you have a mixed up 1.7.x version and a 1.8.x version in the webroot folder. I would empty it and unzip a fresh 1.8.4.1.zip download from your favourite sourceforge mirror.
