Error causes site to 404

[weezieLouise]

trafficstars

Hi, After installing this plugin on magento 9. 2 I get this error

a:5:{i:0;s:240:"Error in file: "/home/mysite/public_html/app/code/community/BL/CustomGrid/sql/customgrid_setup/mysql4-upgrade-0.8.4.4-0.8.9.php" - SQLSTATE[HY000]: General error: 1005 Can't create table 'mysite_234.customgrid_grid_role' (errno: 150)";i:1;s:965:"#0 /home/mysite/public_html/includes/src/Mage_Core_Model_Resource_Setup.php(644): Mage::exception('Mage_Core', 'Error in file: ...')

it brings the whole site down, I have to delete all the files to get it up again, any suggestions?