Comment 4 for bug 1446078

I can confirm the error.
Apache log level looks fine, but the horizon-related logs seems to be coming out as errors all the time:

[Wed Mar 15 10:04:29.260787 2017] [:error] [pid 39]
[Wed Mar 15 10:04:29.261830 2017] [:error] [pid 39]
[Wed Mar 15 10:04:29.261858 2017] [:error] [pid 39] REQ: curl -i http://10.142.0.1:9696/v2.0/floatingips.json?tenant_id=f5e2907a00314b9885cf01f5766f38d1 -X GET -H "User-Agent: python-neutronclient" -H "X-Auth-Token: 18c4f815438542c5bd05bb864d0dece1"
[Wed Mar 15 10:04:29.261872 2017] [:error] [pid 39]
[Wed Mar 15 10:04:29.291733 2017] [:error] [pid 39] RESP:200 {'date': 'Wed, 15 Mar 2017 15:04:29 GMT', 'content-length': '19', 'content-type': 'application/json; charset=UTF-8', 'connection': 'keep-alive'} {"floatingips": []}
[Wed Mar 15 10:04:29.291769 2017] [:error] [pid 39]
[Wed Mar 15 10:04:29.291971 2017] [:error] [pid 39] port_list(): params={'tenant_id': u'f5e2907a00314b9885cf01f5766f38d1'}
[Wed Mar 15 10:04:29.292183 2017] [:error] [pid 39]
[Wed Mar 15 10:04:29.292196 2017] [:error] [pid 39] REQ: curl -i http://10.142.0.1:9696/v2.0/ports.json?tenant_id=f5e2907a00314b9885cf01f5766f38d1 -X GET -H "User-Agent: python-neutronclient" -H "X-Auth-Token: 18c4f815438542c5bd05bb864d0dece1"
[Wed Mar 15 10:04:29.292199 2017] [:error] [pid 39]
[Wed Mar 15 10:04:29.404507 2017] [:error] [pid 39] RESP:200 {'date': 'Wed, 15 Mar 2017 15:04:29 GMT', 'content-length': '13', 'content-type': 'application/json; charset=UTF-8', 'connection': 'keep-alive'} {"ports": []}
[Wed Mar 15 10:04:29.404546 2017] [:error] [pid 39]
[Wed Mar 15 10:04:29.404887 2017] [:error] [pid 39]
[Wed Mar 15 10:04:29.404938 2017] [:error] [pid 39] REQ: curl -i http://10.142.0.1:9696/v2.0/quotas/f5e2907a00314b9885cf01f5766f38d1.json -X GET -H "User-Agent: python-neutronclient" -H "X-Auth-Token: 18c4f815438542c5bd05bb864d0dece1"
[Wed Mar 15 10:04:29.404946 2017] [:error] [pid 39]
[Wed Mar 15 10:04:29.437469 2017] [:error] [pid 39] RESP:200 {'date': 'Wed, 15 Mar 2017 15:04:29 GMT', 'content-length': '84', 'content-type': 'application/json; charset=UTF-8', 'connection': 'keep-alive'} {"quota": {"port": 50, "subnet": 10, "floatingip": 50, "network": 10, "router": 10}}
[Wed Mar 15 10:04:29.437516 2017] [:error] [pid 39]
[Wed Mar 15 10:04:33.204418 2017] [:error] [pid 39] adding enforcer for service: compute
[Wed Mar 15 10:04:33.204668 2017] [:error] [pid 39] adding enforcer for service: network
[Wed Mar 15 10:04:33.204811 2017] [:error] [pid 39] adding enforcer for service: image
[Wed Mar 15 10:04:33.205092 2017] [:error] [pid 39] adding enforcer for service: telemetry
[Wed Mar 15 10:04:33.205211 2017] [:error] [pid 39] adding enforcer for service: volume
[Wed Mar 15 10:04:33.205504 2017] [:error] [pid 39] adding enforcer for service: orchestration
[Wed Mar 15 10:04:33.205683 2017] [:error] [pid 39] adding enforcer for service: identity