Re: I have make an installation error
Which version of bbPress are you using?
If you have phpMyAdmin access, then open the usermeta table (should be bb_capabilities if you are not using shared user tables and should be wp_capabilities if you are using shared tables) and change the value of bb_capabilities to a:1:{s:9:"keymaster";b:1;}
for your user.
Hope that helps.
P.S. – Change the default table prefixes as your case may be.