Form Sessions disconnected frequently for All Ebs Users

Hello everyone,

Our environnement is EBS 12.1.3 and database 11.2.0.4 on AIX 7.2

as more users User's forms session's disconnect randomly and throwing this error message :

FRM-92102: A network error has occurred. The Forms Client has attempted to reestablish its connection to the Server 5 time(s) without success

Changes we made before this error appears :

We applied patches as per note 2188898.1 to enable Java Web start it's included two patches forms .

Change the storage platfome from IBM XIV Fibre Channel storage to   nutanix iSCSI storage

And forms application.log we can find errors like :

21/03/17 15:38:02.112 formsweb: Forms session <237> exception stack trace:

java.io.IOException: FRM-93000: Unexpected internal error.