Wordpress can't detect any thumbnails size?

Question:

Wordpress can't detect any thumbnails size, I re-generated all image but not work.

The plugin (Simple Image Sizes) can detected all thumbnails size settings. 

But when I want to use, it can't detect any size. 

What should i do for this?

Answer:

I found solution, my aws server doesn't have php-gd, just install it.

But, the second problem is wordpress doesn't upload files to correct path (current month is 2017/12), it always upload files to folder "01".