I used my moms sugar cookie recipe that our family and I have used for years. For some reason the dough was real dry and crumbly. I took it out and formed it and it was real hard. It calls for at least 3 hours refrigeration. Well now it is even harder. It usually is on the stickier side. Is there a way to save it?
Did you measure by cups or otherwise by volume, as opposed to by weight? I'd bet that this is the issue, too much flour compared to the rest of the ingredients. Have you made these cookies often enough that you can feel when they're right? You can still save them by adding everything else a bit at a time, and feel for the right texture. Feel, don't look, and let your fingers tell you the answers. Take your time and listen to your fingers. It sounds cliche, but I think it is your best shot.