Icons in the front-end are not showing

Nextcloud version: 19.0.3
Operating system and version : Debian Buster
Apache or nginx version: nginx 1.14.2
PHP version: 7.3.24
Yunohost 4.0.8.2 I know that maybe is a problem with yunohost, but I post it here in case it is related to nextcloud configuration.

The issue you are facing:
Some icons (such as user logo, “+” on Directory navigation, etc…) doesn’t show.

Screenshots:
image

image

Is this the first time you’ve seen this error?: Y

The output of your Nextcloud log in Admin > Logging:

Log
Level	App	Message		Time
Error	core	Following symlinks is not allowed ('/home/yunohost.multimedia/elena//Share' -> '/home/yunohost.multimedia/share/' not inside '/home/yunohost.multimedia/elena/')	
2020-11-18T08:00:02+0100
Error	core	Following symlinks is not allowed ('/home/yunohost.multimedia/elena//Share' -> '/home/yunohost.multimedia/share/' not inside '/home/yunohost.multimedia/elena/')	
2020-11-18T07:45:02+0100
Error	core	Following symlinks is not allowed ('/home/yunohost.multimedia/elena//Share' -> '/home/yunohost.multimedia/share/' not inside '/home/yunohost.multimedia/elena/')	
2020-11-18T07:30:03+0100
Error	PHP	count(): Parameter must be an array or an object that implements Countable at /var/www/nextcloud/apps/richdocuments/lib/Service/CapabilitiesService.php#63	
2020-11-18T07:25:41+0100
Error	PHP	count(): Parameter must be an array or an object that implements Countable at /var/www/nextcloud/apps/richdocuments/lib/Service/CapabilitiesService.php#63	
2020-11-18T07:25:37+0100
Error	PHP	count(): Parameter must be an array or an object that implements Countable at /var/www/nextcloud/apps/richdocuments/lib/Service/CapabilitiesService.php#63	
2020-11-18T07:22:13+0100
Error	core	Following symlinks is not allowed ('/home/yunohost.multimedia/elena//Share' -> '/home/yunohost.multimedia/share/' not inside '/home/yunohost.multimedia/elena/')	
2020-11-18T07:15:02+0100
Error	PHP	count(): Parameter must be an array or an object that implements Countable at /var/www/nextcloud/apps/richdocuments/lib/Service/CapabilitiesService.php#63	
2020-11-18T07:04:50+0100
Error	core	Following symlinks is not allowed ('/home/yunohost.multimedia/elena//Share' -> '/home/yunohost.multimedia/share/' not inside '/home/yunohost.multimedia/elena/')	
2020-11-18T07:00:02+0100
Error	core	Following symlinks is not allowed ('/home/yunohost.multimedia/elena//Share' -> '/home/yunohost.multimedia/share/' not inside '/home/yunohost.multimedia/elena/')	
2020-11-18T06:45:02+0100
Error	core	Following symlinks is not allowed ('/home/yunohost.multimedia/elena//Share' -> '/home/yunohost.multimedia/share/' not inside '/home/yunohost.multimedia/elena/')	
2020-11-18T06:30:03+0100

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

<?php
$CONFIG = array (
  'passwordsalt' => 'XXXXXXX',
  'secret' => 'XXXXX¡,
  'trusted_domains' => 
  array (
    0 => 'localhost',
    1 => 'mcosta.nohost.me',
  ),
  'datadirectory' => '/home/yunohost.app/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '19.0.3.1',
  'overwrite.cli.url' => 'https://mcosta.nohost.me',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'nextcloud',
  'dbpassword' => 'XXXXXXXXXXXX',
  'installed' => true,
  'instanceid' => 'oc2b0v3g78ao',
  'ldapIgnoreNamingRules' => false,
  'ldapProviderFactory' => 'OCA\\User_LDAP\\LDAPProviderFactory',
  'updatechecker' => false,
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'integrity.check.disabled' => true,
  'filelocking.enabled' => true,
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'redis' => 
  array (
    'host' => 'localhost',
    'port' => 'XXXX',
    'timeout' => '0.0',
    'password' => '',
  ),
  'logout_url' => 'https://mcosta.nohost.me/yunohost/sso/?action=logout',
  'maintenance' => false,
  'loglevel' => 2,
  'hashing_default_password' => true,
);

The output of your Apache/nginx/system log in /var/log/____:

Log
2020/11/18 08:08:25 [error] 1512#1512: *652 lua entry thread aborted: runtime error: /usr/share/ssowat/access.lua:276: Interrupted system call
stack traceback:
coroutine 0:
        [C]: in function '(for generator)'
        /usr/share/ssowat/access.lua:276: in function 'scandir'
        /usr/share/ssowat/access.lua:303: in function 'serveYnhpanel'
        /usr/share/ssowat/access.lua:321: in function </usr/share/ssowat/access.lua:1>, client: 62.117.243.232, server: mcosta.nohost.me, request: "GET /nextcloud/core/img/mastodon.svg HTTP/2.0", host: "mcosta.nohost.me"
2020/11/18 08:08:25 [error] 1512#1512: *652 lua entry thread aborted: runtime error: /usr/share/ssowat/access.lua:276: Interrupted system call
stack traceback:
coroutine 0:
        [C]: in function '(for generator)'
        /usr/share/ssowat/access.lua:276: in function 'scandir'
        /usr/share/ssowat/access.lua:303: in function 'serveYnhpanel'
        /usr/share/ssowat/access.lua:321: in function </usr/share/ssowat/access.lua:1>, client: 62.117.243.232, server: mcosta.nohost.me, request: "GET /nextcloud/core/img/rss.svg HTTP/2.0", host: "mcosta.nohost.me"
2020/11/18 08:08:25 [error] 1512#1512: *652 lua entry thread aborted: runtime error: /usr/share/ssowat/access.lua:276: Interrupted system call
stack traceback:
coroutine 0:
        [C]: in function '(for generator)'
        /usr/share/ssowat/access.lua:276: in function 'scandir'
        /usr/share/ssowat/access.lua:303: in function 'serveYnhpanel'
        /usr/share/ssowat/access.lua:321: in function </usr/share/ssowat/access.lua:1>, client: 62.117.243.232, server: mcosta.nohost.me, request: "GET /nextcloud/core/img/mail.svg HTTP/2.0", host: "mcosta.nohost.me"

I found the solution in this github thread:

Basically, changing the color in theming app restored the missing icons.