WebUI not showing files even though webdav and other clients are working fine

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Steps to reproduce
1.Login to webUI successfully and files are not there

Expected behaviour
Expecting files to be there

Actual behaviour
Files missing in WebUI but appear in WebDav and desktop client. All other webUI functions appear to work properly.
Until you make a change on the desktop. Then I get an error : "Server replied file is locked".

Server configuration
Operating system: "Ubuntu precise (12.04.5 LTS)" w/all the latest patches
Web server: Apache 2.2.22
Database: Mysql 5.5.54
PHP version: 5.4.45-4+
ownCloud version (see ownCloud admin page):
Updated from an older ownCloud or fresh install: Fresh install UI + upgraded DB
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption):

ownCloud configuration

    "system": {
        "instanceid": "xxx",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
        "datadirectory": "\/data2\/owncloud",
        "overwrite.cli.url": "https:\/\/mydomain\/owncloud",
        "dbtype": "mysql",
        "version": "",
        "dbname": "owncloude",
        "dbhost": "localhost",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "logtimezone": "UTC",
        "installed": true,
        "theme": "",
        "loglevel": 2,
        "maintenance": false,
        "singleuser": false,
        "mail_from_address": "myname",
        "mail_smtpmode": "php",
        "mail_domain": "gmail.com"

ownCloud log (data/owncloud.log)

Please paste possible errors in the following code block, see https://central.owncloud.org/t/how-to-find-webserver-or-oc-logfile-enable-php-logfile/808 for more info

mydomain.com/:56 GET https://mydomain.com:4545/owncloud/core/vendor/davclient.js/lib/client.js?v=b015ab17af04587a6899a57c4e57ad2d
jquery-migrate.min.js?v=b015ab1.:2 JQMIGRATE: Migrate is installed, version 1.4.0
mydomain.com/:56 GET https://mydomain.com:4545/owncloud/core/vendor/davclient.js/lib/client.js?v=b015ab17af04587a6899a57c4e57ad2d 500 (Internal Server Error)
client.js?v=b015ab1.:59 Uncaught ReferenceError: dav is not defined
    at Client (client.js?v=b015ab1.:59)
    at Object.OC.Files.getClient (client.js?v=b015ab1.:744)
    at Object.initialize (app.js?v=b015ab1.:90)
    at app.js?v=b015ab1.:314
    at underscore.js?v=b015ab1.:768
Client @ client.js?v=b015ab1.:59
OC.Files.getClient @ client.js?v=b015ab1.:744
initialize @ app.js?v=b015ab1.:90
(anonymous) @ app.js?v=b015ab1.:314
(anonymous) @ underscore.js?v=b015ab1.:768
###php-errors.log content
[04-May-2017 17:00:04 America/Denver] PHP Warning:  Module 'apc' already loaded in Unknown on line 0
[04-May-2017 17:00:16 America/Denver] PHP Parse error:  syntax error, unexpected 'version' (T_STRING) in /var/www/owncloud/core/vendor/davclient.js/lib/client.js on line 58
[04-May-2017 17:00:16 America/Denver] PHP Parse error:  syntax error, unexpected 'version' (T_STRING) in /var/www/owncloud/core/vendor/davclient.js/lib/client.js on line 58

Integrity status for oC9+

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