I'm afraid we can't tell much of anything from the minimal information you gave us. Your template file has an extension that might be preventing Photoshop from loading it. Your Photoshop version and OS might be helpful to know, too.
Is it Photoshop or Elements? Which version? Which template extension (.psd, .tif) ? A common problem with Elements is that it does not accept layer groups (at least without external add-ons like Elements+). That is solved in Elements 15.