I just purchased xfilesharing pro and was wondering what the add server option under server management was for?

I am getting this error on a new install of xfilesharing pro: Forbidden You don't have permission to access /files/4/2q4ea1flye3dfu/Bible_Highlights.pdb on this server. Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request. I get this error af...