Error 404, but the content is displayed

Hi all !

I cant figure why I get a 404 error.
I started my project two days ago, and I’m not use to work with WP, but I did some javascript with node and angular. I have to make something who look like that.

I took Grid, and begin to work on the grid for the index. As I dont know WP, I dont know if chosing this theme was the right decision. The infinit scroll dont work after my changes so I managed to write my own with a tutorial, all was going well before this error. So, my script do a get request on the next page, and, on success, display all the article. It work for the firsts pages.
But, for the lasts pages, even if the content is display (as I can see when I enter the url directly in my browser), the 404 ruins everything.

I readed a lot about this issues and I already try some solutions;
-switch permalink’s setting and save in order to refresh it
-I activated rewrite_module on my Apache setting (I’m in local with Wamp 2.5)

How can I fix this ?
Should I swith to another theme for my project ?

Really sorry for my terrible english, I’m french, and thank you for you time !