I cannot access my post.

I cannot reach this post.https://blenderartists.org/forum/showthread.php?417800-the-Endless-runner-car-game&highlight=marcoit's+endless+runner
It is a bad.It is my post.
Your browser sent a request that this server could not understand.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Apache/2.2.24 (Unix) mod_hive/5.5 mod_ssl/2.2.24 OpenSSL/1.0.0-fips mod_auth_passthrough/2.1 mod_bwlimited/1.4 mod_fastcgi/2.4.6 mod_fcgid/2.3.6 Server at blenderartists.org Port 443:confused:

Seems to work fine here: https://blenderartists.org/forum/showthread.php?417800-the-Endless-runner-car-game
Your problem is the highlight tag at the end of your link, which contains a non-standard character (’) that this website does not especially like.