LEFT JOIN on access

I am trying to use the left join for a specific temporary mod on webwiz 8.0 but I failed use the LEFT JOIN. If I am using the INNER JOIN everything is OK, but I get no desired result.

the error I get is: Join expression not supported.

please help me with the query:

 

 

SELECT mainforum.forum_id, mainforum.sub_id, tblForum.Forum_ID, tblForum.Forum_name, tblForum.Sub_ID, tblForum.Password, tblForum.Forum_code, tblTopic.Topic_ID, tblTopic.Poll_ID, tblTopic.Moved_ID, tblTopic.Subject, tblTopic.Icon, tblTopic.Start_Thread_ID, tblTopic.Last_Thread_ID, tblTopic.No_of_replies, tblTopic.No_of_views, tblTopic.Locked, tblTopic.Priority, tblTopic.Hide, tblThread.Message_date, tblThread.Message, tblThread.Author_ID, tblAuthor.Username, LastThread.Message_date, LastThread.Author_ID, LastAuthor.Username
FROM tblCategory, tblTopic, tblThread, tblThread AS LastThread, tblAuthor, tblAuthor AS LastAuthor,
tblForum LEFT JOIN tblforum AS mainforum ON mainforum.Forum_id=tblforum.sub_id
WHERE tblCategory.Cat_ID=tblForum.Cat_ID AND tblCategory.Cat_ID=4 AND tblForum.Forum_ID=tblTopic.Forum_ID AND tblThread.Author_ID=tblAuthor.Author_ID AND LastThread.Author_ID=LastAuthor.Author_ID AND tblTopic.Start_Thread_ID=tblThread.Thread_ID AND tblTopic.Last_Thread_ID=LastThread.Thread_ID AND (tblTopic.Forum_ID IN (SELECT tblPermissions.Forum_ID FROM tblPermissions WHERE (tblPermissions.Group_ID = 1 OR tblPermissions.Author_ID = 1) AND tblPermissions.View_Forum=true))AND (tblTopic.Hide=false OR tblThread.Author_ID=1)
ORDER BY tblForum.Sub_ID, tblForum.Forum_ID, tblCategory.Cat_order, tblForum.Forum_Order, LastThread.Message_date;