[Buddypress] Problem during activation plugin

Hello

i have problem while i am activating Buddypess plugin.

When i activate it there is error:
“Nie posiadasz wystarczaj?cych uprawnień, by wej?? na t? stron?.”

It means “You have no rigts to enter this site”

And i cant go to Admins panel cuz of that error.

After that i removed buddypress files from my server, and now it works fine.

But i want to install buddypress.

Anybody know what should i do?