Custom sidebars locked after import

I just installed custom sidebars pro. I can't select a sidebar in my post. It gives this message:

Here you can replace the default sidebars. Simply select what sidebar you want to show for this post! All sidebars have been locked, you cannot replace them. Go to the widgets page to unlock a sidebar.

I don't see an option to unlock a sidebar. Please assist. I have enabled support access.