Old post but feel the need to share, I had two cricket escape issues.
1. The crickets were climbing the wall in the back of my exo terra terrarium and escaping through the wire holes
2. I bought the Lee's Cricket Feeder, and they were climbing out of the bigger holes in the top of the feeder!

I used whether striping(purchase at your local auto parts store) for the cage and just scotch tape on the big holes of the feeder!