What OS was this? OEL/RHEL? What version of the apps are you using? When changing the OS, you need to relink the entire applications (all Oracle Home and all executables).
R11i / R12 : How to relink an E-Business Suite Installation of Release 11i and Release 12.x ? (Doc ID 356878.1)
If you are on 12.1, you need to ensure you are on the latest supported technology stack versions including JDK 7 in order to run on OEL/RHEL 7.X.
Oracle E-Business Suite Installation and Upgrade Notes Release 12 (12.1.1) for Linux x86-64 (Doc ID 761566.1)
Interoperability Notes EBS 12.0 and 12.1 with Database 11gR2 (Doc ID 1058763.1)
Interoperability Notes EBS 12.0 or 12.1 with RDBMS 12cR1 (Doc ID 1524398.1)
Oracle E-Business Suite Release 12.1.3 Readme (Doc ID 1080973.1)
Upgrading to the Latest OracleAS 10g 10.1.3.x Patch Set in Oracle E-Business Suite Release 12 (Doc ID 454811.1)
Upgrading OracleAS 10g Forms and Reports in Oracle E-Business Suite Release 12 (Doc ID 437878.1)
Using JDK 7.0 Latest Update with Oracle E-Business Suite Release 12.0 and 12.1 (Doc ID 1467892.1)
Actually its not new installation its our test instance on which we have upgraded the Os from 6.1 to 7.1 aix from that onwards i a mfacing issue i have done everything relink addfcg autoconfig ran gather schema stat as applysys or fnd also ,
and whenver i am running any request it running normal not completing,
even now e have downgraded the OS to 6.1 also.