why does crust/key lime bars crumble when cutting

[golfergirlj]

Making several batches of key lime bars. The crust is basic 2c. flour, 2 sticks butter and 1/2 c. powdered sugar- bake 20-25 minutes. And then do the rest, etc.
It's a standard key lime (like lemon) bar recipe- nothing different/"interesting".
The first batch cut and came out fine. I baked the crust the lower end- 20 mintes. Thought it was a tad underbaked, so next batch baked the crust part 25 minutes.
This second batch was a mess cutting and getting out of the pan. It's not that it stuck to the pan. Rather, the crust part of these key limes bars kind of crumbled all over the place.
What the heck causes that? Overbaking? Would like for that not to happen with the next batch I make. Using for a party. yikes And so much darn work/$$ squeezing these real key limes (tiny, tiny things!).
Thanks for any hints. I thought I was a pretty good baker, but stumped.

[Dee514]

It could be caused by several things....
overbaking the crust, not packing the crust firmly enough in the pan, slicing them when they are too hot or too cold, they should be warmer than room temp when sliced.

[golfergirlj]

Thanks for those hints!

[iewe]

I have had the same issue with my bar type things in the past like that -- thanks for the hints!