Logstash complains permission denied when the file is owned by logstash user

I keep on getting this in the logstash log where Logstash complains saying unable to open the file (permission denied), but the file actually is set to belong the logstash user.

Any idea why?

root@PROD-logger-10-2-200-87:/var/log/logstash# tail -n1 logstash.log
{:timestamp=>"2016-03-09T07:18:30.794000+0000", :message=>"failed to open /log/app/applog-today.log: Permission denied - /log/app/applog-today.log", :level=>:warn}

root@PROD-logger-10-2-200-87:/var/log/logstash# ll /log/app/applog-today.log
-rwxrwxrwx 1 logstash logstash 23374 Mar  9 06:16 /log/app/applog-today.log

Check the permissions of the /log and /log/app directories. The Logstash users needs at least execute permission for those.

It does... I have recursively changed to 777 for the whole folder.