Maximum number of file OwnCloud can sync

Please help us by providing the following info.

Steps to reproduce
1. Install OwnCloud Server

Expected behaviour
Tell us what should happen

Actual behaviour
Tell us what happens instead

Client configuration
Client version:
Client operating system:

Server configuration
Operating system: Ubuntu 14.04
Web server: Apache 2.4.7
Database: MySQL
PHP version: 5.5.9
ownCloud version (see ownCloud admin page): 7 or 9 (latest)
Updated from an older ownCloud or fresh install:
ownCloud log (data/owncloud.log):

Special configurations (external storage, external authentication, reverse proxy, server-side-encryption):

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