ERROR 502 WOOPS not responding (again)

Hello everyone, i had install Gitlab on my Raspbery Pi2 and it worked, but two days ago, i tryed to push heavy files on and after that, when i try to connect to it whith my browser, it show me the 502 error message.

I tryed to reinstall it with removing gitlab-ce and reinstall it, but i got the same issue. I read many topics about this problem, but no solution proposed can fix mine.

I need your help. Please ask me what you need to help me.

Thank you.