Please fix the following input errors:

There were errors when trying to populate the database:
Executing: CREATE TABLE ls_participant_attribute_names_lang ( attribute_id int(11) NOT NULL, attribute_name varchar(30) NOT NULL, lang varchar(255) NOT NULL, PRIMARY KEY (attribute_id,lang) ) ENGINE=MYISAM CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci; failed! Reason: exception 'CDbException' with message 'CDbCommand failed to execute the SQL statement: SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 1000 bytes' in /home/francoisr/www-sf/sondage/framework/db/CDbCommand.php:358 Stack trace: #0 /home/francoisr/www-sf/sondage/application/controllers/InstallerController.php(990): CDbCommand->execute() #1 /home/francoisr/www-sf/sondage/application/controllers/InstallerController.php(960): InstallerController->executeSQLFile('/home/francoisr...', 'ls') #2 /home/francoisr/www-sf/sondage/application/controllers/InstallerController.php(577): InstallerController->_setup_tables('/home/francoisr...') #3 /home/francoisr/www-sf/sondage/application/controllers/InstallerController.php(79): InstallerController->stepPopulateDb() #4 /home/francoisr/www-sf/sondage/framework/web/CWebApplication.php(282): InstallerController->run('populatedb') #5 /home/francoisr/www-sf/sondage/framework/web/CWebApplication.php(141): CWebApplication->runController('installer/popul...') #6 /home/francoisr/www-sf/sondage/framework/base/CApplication.php(184): CWebApplication->processRequest() #7 /home/francoisr/www-sf/sondage/index.php(211): CApplication->run() #8 {main}