The Apache logs don't show any page generation error, so the most likely issue is that you have an intervening firewall which is doing something stupid.
adam. On 16/06/2017 09:26:38, Давыдов Денис da.davydov@i-teco.ru wrote: Hello everybody! We use Observium Subscription Edition Version: Observium 17.5.8580 (stable) SVN info: [root@tnobspapp01 observium]# svn info Path: . Working Copy Root Path: /opt/observium URL: http://svn.observium.org/svn/observium/branches/stable [http://svn.observium.org/svn/observium/branches/stable] Repository Root: http://svn.observium.org/svn [http://svn.observium.org/svn] Repository UUID: 61d68cd4-352d-0410-923a-c4978735b2b8 Revision: 8662 Node Kind: directory Schedule: normal Last Changed Author: adama Last Changed Rev: 8580 Last Changed Date: 2017-05-28 15:05:18 +0300 (Sun, 28 May 2017) OS: [root@tnobspapp01 ~]# cat /etc/redhat-release CentOS Linux release 7.3.1611 (Core) Kernel: [root@tnobspapp01 ~]# uname -a Linux tnobspapp01 3.10.0-514.16.1.el7.x86_64 #1 SMP Wed Apr 12 15:04:24 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux Selinux: [root@tnobspapp01 observium]# getenforce Permissive PHP version: [root@tnobspapp01 ~]# php -v PHP 7.0.19 (cli) (built: May 12 2017 21:01:27) ( NTS ) Copyright (c) 1997-2017 The PHP Group Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies with Zend OPcache v7.0.19, Copyright (c) 1999-2017, by Zend Technologies Apache version: [root@tnobspapp01 ~]# httpd -v Server version: Apache/2.4.6 (CentOS) Server built: Apr 12 2017 21:03:28 Problem: In browser (Chrome, IE, Firefox): Devices -> All devices -> Choose any device -> Properties -> choose MIBs or Modules = This page isn’t working ERR_EMPTY_RESPONSE In Apache access log: 172.XX.XX.XX - - [15/Jun/2017:10:43:45 +0300] "GET /device/device=530/tab=edit/section=modules/ HTTP/1.1" 200 134939 "-" "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36" 172.XX.XX.XX - - [15/Jun/2017:10:46:22 +0300] "GET /device/device=530/tab=edit/section=mibs/ HTTP/1.1" 200 157018 "-" "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36" What is it? Bug? Please help me. Best regards, Davydov Denis