Internal Server Error I can't interpret

ℹ️ Support
1

Nextcloud version (15.0.4):
Operating system and version (Ubuntu 18.10):
Apache or nginx version (nginx 1.15.5):
PHP version (eg, 7.2):

The issue you are facing: I get an internal server error pointing me to the server log, but I’m green enough to not know exactly where to find it. I can find access.log and error.log; is it one of these? Thanks, everyone, for taking pity on a poor noob!

Is this the first time you’ve seen this error? (N):

Steps to replicate it:

  1. Point my browser to localhost/nextcloud.index.php
2

The error.log sounds right, if it is configured by nginx. Is there content in the error.log? If not, increase the log level of the web server.

3

Okay, here’s the content from the error.log:

PHP message: {“reqId”:“7UuoqE0c36OK601i22FC”,“level”:3,“time”:“2019-02-28T02:38:25+00:00”,“remoteAddr”:“192.168.1.133”,“user”:"–",“app”:“PHP”,“method”:“GET”,“url”:"/nextcloud/index.php",“message”:“chmod(): Permission denied at /var/www/html/nextcloud/lib/private/Log/File.php#141”,“userAgent”:“Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:65.0) Gecko/20100101 Firefox/65.0”,“version”:""}" while reading upstream, client: 192.168.1.133, server: _, request: “GET /nextcloud/index.php HTTP/1.1”, upstream: “fastcgi://unix:/var/run/php/php7.2-fpm.sock:”, host: “192.168.1.101”, referrer: “http://192.168.1.101/nextcloud/index.html”

I’m confused by the backslash-forwardslash separators in the pathnames. Is there a reason they’re not just /? Is that a PHP thing?

Ken