error:
Duplicate key name 'user_nicename'
>>> User tables will already exist when performing a database integrated installation.
Forum could not be created!
and
Step 1 - Creating database tables
>>> Create table bb_forums
>>> Create table bb_posts
>>> Create table bb_topics
>>> Create table bb_topicmeta
>>> Create table bb_tags
>>> Create table bb_tagged
>>> Added index wp_users UNIQUE KEY user_nicename (user_nicename)
>>>
>>>>>> Duplicate key name 'user_nicename'
How can I fix this?