Pool walls bending in

[Jwhiddon77]

Recently installing an above ground pool, I checked everything and it looked correct, until I started filling it, I have about 8 inches of water and the walls at the top started to bend it, not sure if the liner is too tight or maybe another issue, any advice is appreciated.

 

[Texas Splash]

Definitely something is off, but I can't pick out the root cause. @zea3 do you have a thought?

 

[zea3]

How warm was it when you began to fill the pool? Did you unfold the liner and allow it to sit in the sun for a couple of hours before you installed it in the pool?