error when trying to clear the cache in drupal
If the on option is grey, it means the module is required by another one. Deleting it will cause other modules to break. The correct thing to do would be to disable the depending modules, then disable the main modules and then go to the 'uninstall' tab and uninstall the module. 

But for now try running update.php (drush updb) first and see if it helps. If not. Uninstall the modules properly, install the previous versions, disable and uninstall the previous versions and then install new versions again.

This works in most cases.