There is an incorrect setting in every forum integration script if you are using Mysql v.5.1 or later.
TYPE=... table option is deprecated and the correct setting is ENGINE=
So if you are trying to do a fresh install, you are using MySQL v.5.1 or later and you are trying to using a forum integration scripts like VB
Installer crashes on step 4 and produces error "We're sorry, but the system experienced an unrecoverable error. Please try again later."
You can fix that by editing the correct forum integration script (eg. vb3.php) and replace
PRIMARY KEY (groupid)) TYPE=MyISAM
PRIMARY KEY (groupid)) ENGINE=MyISAM