Datenbank läßt sich nicht aktualisieren

Hallo,
während der Installation gibt es bei der Datenbankaktualisierung die Fehlermeldung:

Fatal error: Uncaught exception Exception with message Query error: Index column size too large. The maximum column size is 767 bytes. (CREATE TABLE `tl_files` ( `id` int(10) unsigned NOT NULL auto_increment, `pid` binary(16) NULL, `tstamp` int(10) unsigned NOT NULL default '0', `uuid` binary(16) NULL, `type` varchar(16) NOT NULL default '', `path` varchar(1022) NOT NULL default '', `extension` varchar(16) NOT NULL default '', `hash` varchar(32) NOT NULL default '', `found` char(1) NOT NULL default '1', `name` varchar(255) NOT NULL default '', `importantPartX` int(10) NOT NULL default '0', `importantPartY` int(10) NOT NULL default '0', `importantPartWidth` int(10) NOT NULL default '0', `importantPartHeight` int(10) NOT NULL default '0', `meta` blob NULL, PRIMARY KEY (`id`), KEY `pid` (`pid`), UNIQUE KEY `uuid` (`uuid`), KEY `path` (`path`(333)), KEY `extension` (`extension`) ) ENGINE=MyISAM DEFAULT CHARSET=UTF8; ) thrown in system/modules/core/library/Contao/Database/Statement.php on line 295

#0 system/modules/core/library/Contao/Database.php(207): Contao\Database\Statement->query('CREATE TABLE `t...')
#1 system/modules/core/controllers/BackendInstall.php(616): Contao\Database->query('CREATE TABLE `t...')
#2 system/modules/core/controllers/BackendInstall.php(177): Contao\BackendInstall->adjustDatabaseTables()
#3 contao/install.php(24): Contao\BackendInstall->run()
#4 {main}

Leider kann ich damit nichts anfangen. Was muß ich tun?
Joe