Why do such errors appear in apache's error.log?

Question

Apache HTTP Server

The following entries appear in the error log:

2018/05/07 11:54:55 [crit] 29579#29579: *177774 
open() "/home/example/web/example.ru/public_html/images/upload/derevjannye-kresla-skladnaja-mebel-iz_57_1.jpg" 
failed (13: Permission denied), client: 188.162.167.148, server: example.ru, 
request: "GET /images/upload/derevjannye-kresla-skladnaja-mebel-iz_57_1.jpg HTTP/1.1", 
host: "example.ru", referrer: "https://www.google.ru/"

When I try to open the media file using the browser listed in the error log, I have no problems. Where to look for a solution to the problem?

Answer 1

Either apache or nginx didn't have enough permissions to read the files in the website folder. I had to change the rights from 600 to 644 and the problem is no more.