Hello Cakers

I took my lovely cake (9" round, chocolate) out of the freezer last night to fill and crumb coat before work and when I leveled the top, one whole side fell away from the cake! It was like there was a hole there or something! What did I do wrong? Never had this trouble before...

Thanks for any help. It wasn't fun trying to re-bake a new cake before work this morning...grrrrr....

What recipe did you use?

Durable 3D

I've never had a problem before

No ideas anyone?