I think in your site compilation is on So follow below solution
Turn Off the compiler from your terminal steps
- Open your terminal /connect your ssh access
- Go to your magento root via this command
- Fire this commnad
php -f compiler.php disable
- After this do compile
php -f compiler.php compile
- After this enable compile
php -f compiler.php enable
- Go to your module's xml file located in
app/etc/modulesand disable the module
- Clear the cache
- Now you are able to login in back end
- Disable the compiler and install your module
- Go compile and enable your magento compile
Have you installed any custom extension regarding wishlist?
Meanwhile please try below process:
Reïndex all indexes: php ./shell/indexer.php -reindexall
Delete cache: rm -rf var/cache/* or Rename the cache folder under var to Cache_backup.
It may occur because wishlist_item table is not present in DB. If you have backup of your DB please try to add that table.