Be sure that neither the attachment nor the vacuum itself is visibly damaged or malfunctioning in any way. If necessary, gently clean the vacuum and either the brush or extension wand with a damp cloth, as any accumulated dirt, dust, or debris may prevent you from connecting an attachment to the vacuum. The dust collector should be firmly attached into place on the vacuum, so that the extension wand can easily be inserted into its opening, and the dust brush can be connected to the end of the wand. All pieces should easily snap into place. If you’re still having trouble, reach out to Customer Service for further assistance.