net::ERR CONTENT LENGTH MISMATCH

Content length errors occur when there is a byte difference between the size of the response in the header compared to the actual size of the response document.

“Content-Length mismatch: Response Header claimed 1767884 bytes, but server sent 1772317 bytes.”

Recently, these issues began creeping up for me in a few rails + sinatra projects and I had recently upgrade nginx.

GET https://subdomain.mysite.com/assets/application.css net::ERR_CONTENT_LENGTH_MISMATCH
GET https://subdomain.mysite.com/assets/application.js net::ERR_CONTENT_LENGTH_MISMATCH

Thats when theses issues started appearing on the client side.

Start by taking a look at your HTTP servers logs:

tail -f /usr/local/var/log/nginx/error.log

Refresh your asset - you may see something like:

“/usr/local/var/run/nginx/proxy_temp/9/04/0000000049” failed (13: Permission denied) while reading upstream

Heres how I fixed:

sudo nginx -s stop
sudo rm -rf /usr/local/var/run/nginx/*

The /usr/local/var/run/nginx directory holds tmp data describing nginx since it was booted. Files under this directory are removed at the beginning of the boot process and can be safeley deleted.

Have you made any changes to your server configuration recently?

If all else fails, clear out stale assets and try restarting your http server.