Question to the experts.

A new book arrived looking like this. The other ones in the package were fine.

Is it humidity or improper storage? Any idea/way to remedy this?

https://preview.redd.it/6wv9d9zl3xke1.jpg?width=4080&format=pjpg&auto=webp&s=93541929e86da0f582e5c82817657a8aeb191f03

https://preview.redd.it/o41txn0n3xke1.jpg?width=4080&format=pjpg&auto=webp&s=8c4fadf81c65b6266a9807c20dfab7b1109885b0