FRM-92050 failed to connect to Server /forms/servlet -1

Problem:
Recently while upgrading one of our Oracle EBS environment from release 11.5.10.2 to Release 12.1.1, we had this issue while trying to any Form using MS Internet Explorer Browser Version 10 from R12 EBS front end url.

Cause:

The required Forms 10.1.2.3 servlet components may not have been deployed properly when Forms 10.1.2.3 was first installed in your Oracle E-Business Suite Release 12 environment (Bug 8608695).

Solution:

To fix this I disabled XSS filter under IE Security settings and it started working fine.

Internet Explorer -> Internet Options -> Security -> Click on Internet -> Custom Level -> Disable XSS filter

But this is just a temporary fix, if you want to fix this issue once in for all, you may have to

re-deploy forms.ear file.

Let's take a look at the steps needed to deploy a new formsapp.ear in Oracle E-business Suite Release 12.

1. Source the environment file and stop all the applications or services running on application tier.
   cd $APPL_TOP
   . ./APPS<CONTEXT_NAME>.env
2.   Now we need to change the ocj4jadmin password
   
   $ cd $INST_TOP/ora/10.1.3/j2ee/forms/config/
   $ cp system-jazn-data.xml system-jazn-data.xml.ori
   Now open this .xml file and search for string "credentials
    <credentials>{903}9VrhYTuhd7DyBJf7J/4KwbSEIlETQJOO</credentials> -- before the change
   <credentials>!welcome</credentials> -- after the change
   
   Note: The "!" in "!welcome"is required. The password for the oc4jadmin user is changed to "welcome"
   
   This step can be skipped if you know the password for oc4jadmin, so folks start recording all your password. Also, before changing oc4jadmin password please try oafm or secret as passwords once.
3.  Run Deployment Script
   txkCfgOC4JApp.pl is a perl script that installs the .ear file in the proper location and configures the Forms J2EE group correctly.
   
   Note: Before running this perl script make sure no Java processes are running.
   
   $ cd $FND_TOP/bin/txkrun.pl -script=CfgOC4JApp
   Enter Application name for re-deployment ? forms
   Enter Oc4j Instance password for re-deployment ? welcome (or current password)
   Run Autoconfig <Yes/No> ? No
4. Run AutoConfig on the instance by running the command:
   $ADMIN_SCRIPTS_HOME/adautocfg.sh
5. Start the appropriate services on the instance by running the command:
   $ADMIN_SCRIPTS_HOME/adstrtal.sh <apps user/apps password>

HTH

Thanks for reading..!!