need help with buddypress

i had installled buddypress theme but it gaves me error whenever i clicked on “my account” the error is “HTTP Error 404.0 – Not Found”
i was told to follow the bp steps…but step 2 doent resolve for me ,
and now i installed another theme it takes me through bp compatibility step 3….and says now ur “activity ll run fine ” but it didnt , any 1 can help me with this issue ?
the current theme is BP Columns 1.2 ..!