Forms doesn't launch from self service

I am sure you must have faced this so many times and spent frustating hours debugging it. I'll update this thread with all the possible solutions I have found:

Solution I

Do a ping -s
It should return the correct hostname.domainname
Check whether the hostname.domainname is the value of the context file variable "s_oacore_trusted_oproc_nodes"

grep s_oacore_trusted_oproc_nodes $CONTEXT_FILE

If it is not present, add it in the variable value as ,hostname

Run autoconfig.

Check for the string Allow in Apache configuration files:

grep Allow $IAS_ORACLE_HOME/Apache/Apache/conf/*.conf

Look for the phrase Allow from hostname.domainname

If its not present, add it in all the files.

Bounce Apache

Retest issue

Solution II

vi $IAS_ORACLE_HOME/Apache/Apache/conf/security.conf
Go to end of the file with the vi command: Shift+G
Comment these two lines which begin with SecFilterSelective by placing # before them:

SecFilterSelective "REQUEST_URI" !^/pls/[-a-z0-9_]+/!?[a-z](([a-z0-9_\$#]){0,29})(\.[a-z](([a-z0-9_\$#]){0,29})){0,2}(\?.*
){0,1}$

# Make sure the parameter names contains only valid subset of 7-bit ascii
SecFilterSelective "ARGS_NAMES" !^(([a-z0-9_]){1,30})((\.[a-z0-9_]{1,30}){0,1})$

These lines appear in security.conf after applying ATG_PF.H RUP4 or TXK Rollup O.

Save the file security.conf with vi command :wq

Bounce Apache

Retest issue.

Solution III