Can not access web interface - Error 500

I can not load the web interface. The client ios-app can not connect to the server. I can not use the maintenance tool from owncloud. Every time the same error:
PHP Fatal error: Class 'OC\Cache\CappedMemoryCache' not found in /var/www/owncloud/lib/private/AllConfig.php on line 70
After the last update everything worked and I changed nothing at the system. Suddenly the error happens.
Has anyone an idea?
Thank you in advance!

Steps to reproduce

  1. go to the website:

Expected behaviour

The normal web interface should appear

Actual behaviour


Server configuration

Linux raspberrypi 4.4.50-v7+ #970 SMP Mon Feb 20 19:18:29 GMT 2017 armv7l GNU/Linux

Web server:
Apache/2.4.10 (Raspbian)


PHP version:
PHP Version 5.6.29-0+deb8u1

ownCloud version: (see ownCloud admin page)

Updated from an older ownCloud or fresh install:
update from 9.1 (?) via repository (apt-get update && apt-get upgrade)

Where did you install ownCloud from:

Signing status (ownCloud 9.0 and above):

Login as admin user into your ownCloud and access 
paste the results here.
not possible

List of activated apps:
calender, contacts, ownbackup

If you have access to your command line run e.g.:
sudo -u www-data php occ app:list
from within your ownCloud installation folder

PHP Fatal error:  Class 'OC\Cache\CappedMemoryCache' not found in /var/www/owncloud/lib/private/AllConfig.php on line 70

The content of config/config.php:
'updatechecker' => false,
'instanceid' => 'XXXXX',
'passwordsalt' => 'XXXXX',
'secret' => 'XXXX',
'trusted_domains' =>
array (
0 => 'raspberrypi',
1 => '',
'datadirectory' => '/media/ownclouddrive/',
'overwrite.cli.url' => '',
'dbtype' => 'mysql',
'version' => '',
'dbname' => 'clouddata',
'dbhost' => 'localhost',
'dbtableprefix' => 'oc_',
'dbuser' => 'oc_admin',
'dbpassword' => 'XXXX',
'logtimezone' => 'Europe/Berlin',
'installed' => true,
'mail_from_address' => 'mp',
'mail_smtpmode' => 'smtp',
'mail_domain' => 'XXXX',
'mail_smtpauth' => 1,
'mail_smtpauthtype' => 'LOGIN',
'mail_smtphost' => 'XXXX',
'mail_smtpport' => '587',
'mail_smtpname' => 'XXXX',
'mail_smtppassword' => 'XXXX',
'mail_smtpsecure' => 'tls',
'memcache.local' => '\OC\Memcache\APCu',
'maintenance' => false,
'theme' => '',
'loglevel' => 2,
'logfile' => '/var/log/owncloud.log',
'log_rotate_size' => 104857600,
'debug' => false,

Are you using external storage, if yes which one:

Are you using encryption: no

Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/...

Client configuration

Browser: chrome or firefox, same behaviour


Web server error log

[Fri Apr 07 14:55:37.277904 2017] [:error] [pid 1969] [client] PHP Fatal error:  Class 'OC\\Cache\\CappedMemoryCache' not found in /var/www/owncloud/lib/private/AllConfig.php on line 70

ownCloud log (data/owncloud.log) (Not relevant)

{"reqId":"jrp63ix25PvcPdN\/d57\/","remoteAddr":"","app":"core","message":"Login failed: '(null)' (Remote IP: '')","level":2,"time":"2017-03-28T08:58:33+02:00","method":"GET","url":"\/owncloud\/ocs\/v1.php\/apps\/files_sharing\/api\/v1\/shares","user":"--"}


Unfortunately I still can not access my server, although I cleared the APCu-Cache.
Then I made a complete clean installation via

$ sudo apt-get purge owncloud
$ sudo apt-get purge owncloud-*
$ sudo apt-get autoremove
$ sudo apt-get install owncloud

I restored all files. Now everything works fine.