fatal error: 'bits/libc-header-start.h' file not found - on ide.CS50.com

[Petelja]

Hello. I learn CS50 course and have one problem with compiling some program on web-server ide.CS50.com
I think, that I'm trying to compile 32-bit program on 64-bit machine.
I'm trying every solution that I can found:

1. Added -m32 in every line of make file.
2. Checked tab-symbols in every line of make file.
3. Tryed to install "sudo apt-get install gcc-multilib g++-multilib", "sudo apt-get install gcc-multilib" and "sudo apt install libc6-dev-i386" but saw the massage with "Failed to fetch".

Please, help.

[programmeruser2]

How is this related to the repository?