EBS 12.2 - cloned instanced can not show images / Connection refused: proxy: HTTP: attempt to connect to / GET /OA_MEDIA/oracle_white_logo.png HTTP/1.1" 503

After cloning an EBS 12.2 environment, which has multiple managed servers for certain services, you may face with a image rendering problem.

The problem actually can be encountered after disabling some of the managed servers in a newly clone environments. (Generally, we don't have much load in test/clone environments, so after cloning we disable some of the managed servers  in these environment which are configured to run in parallel in Production environments)

The issue that I m talking about is something like the following image rendering and layout problem, which is shown in the example screenshot below;

The issue depicted in above screenshot was on a newly cloned environment. The customer was not sure when it was started. But following were the changes that are done in this environment;

-disabled the SSL.
-some of the oacore servers in this newly cloned environment.
-applied ATG TXK and AD Delta patches (using online patching cycle)

SSL may be the problem as some of the profiles like APPS_FRAMEWORK_AGENT was still pointing to the https url in the site level.
So I disabled the SSL once again, properly, but the issue have continued.

After analyzing the Oracle HTTP Server logs; these were the findings;

HTTP Server log : [2016-09-22T19:06:33.0646+03:00] [OHS] [ERROR:32] [OHS-9999] [core.c][host_id: servername_deleted_for_security_reasons] [host_addr: 10.111.8.3] [tid: 139926295234304] [user: applmgr] [ecid: 005FHfORQun7q2w5OF0Fyd0006jJ000005] [rid: 0] [VirtualHost: main] (111)Connection refused: proxy: HTTP: attempt to connect to 10.111.8.3:7201 (servername_deleted_for_security_reasonsl) failed

HTTP Server access log: 10.20.10.21 - - [22/Sep/2016:19:06:33 +0300] "GET /OA_MEDIA/oracle_white_logo.png HTTP/1.1" 503 306

So, the HTTP server was trying to reach the port 7201 ( which was the current patch edition port). So there should be a reference left , as the oacore server currently was listening on 7202.
This could be caused by a problematic managed server remove operation or a problem in the cutover phase which was done for applying the AD and TXK delta patches.

The fix that I applied was for deleting the unnecessary managed server references for oacore and it worked.

The solution: perl $FND_TOP/patch/115/bin/txkSetAppsConf.pl -contextfile=$CONTEXT_FILE -configoption=removeMS -oacore=<host_name>:7201