Question AH01070: Error parsing script headers

[Giorgio1]

I need some help to debug this situation!

The problem
I get a lot of these error in apache error_log:

AH01070: Error parsing script headers

Actual settings:

CentoOS 7.4, Plesk Onyx 17.5.3

Hosting settings:
- PHP 7.1.15
- FPM application served by Apache

nginx settings:

"Proxy mode" and "Smart static files processing" enabled.

Additional nginx directives:

gzip on;
gzip_disable "MSIE [1-6]\\.(?!.*SV1)";
gzip_proxied any;
gzip_comp_level 5;
gzip_types text/plain text/css application/javascript application/x-javascript text/xml application/xml application/xml+rss text/javascript image/x-icon image/bmp image/svg+xml;
gzip_vary on;

I found that when I load a page of this Wordpress website with Chrome DevTools > Network -> Disable cache, there are no error. If I uncheck "Disable cache" and I reload the page, apache writes the error in error_log.

In the Wordpress website there is WP Super Cache.

What could be the problem? Thanks for any suggestion.

 

[Giorgio1]

Some more details. In WP Super Cache was active the setting "304 Not Modified browser caching. Indicate when a page has not been modified since it was last requested. (Recommended)".

When I disabled this setting, the status of the page is 200 and it seems that there isn't anymore the error in error_log.

Any comments are welcome...

 

[IgorG]

Most probably this issue related to Apache bug - Error in the Apache error_log: AH01070: Error parsing script headers

 

[Giorgio1]

I read about that but I was not sure it's related. I have also a couple of 503 error in Google Search Console, so I will continue to investigate...