I have the exact same problem.
My server info is
OS: Linux crossadaptive 3.19.0-58-generic #64~14.04.1-Ubuntu SMP Fri Mar 18 19:05:43 UTC 2016 x86_64
PHP version: 5.5.9-1ubuntu4.16
WordPress version: 4.5.2
WordPress multisite: No
openssl: Available
allow_url_fopen: Enabled
stream_socket_client: Available
fsockopen: Available
