Firefox error: "PR_END_OF_FILE_ERROR" when attempting to access the Enforce console

Products

• Data Loss Prevention
• Data Loss Prevention Enforce
• Data Loss Prevention Oracle Standard Edition 2

Issue/Introduction

Symantec Data Loss Prevention (DLP)
Oracle 12.2.0.1 Enterprise in a two server grid

In preparation for upgrading Oracle to 19c, the DBA installed Oracle patch 28553832.

After installing that patch, no one can access the Enforce console.

Firefox throws an error saying "PR_END_OF_FILE_ERROR".
Both Chrome and I.E. throw a time-out error.

Restarting the DLP services does not resolve this issue.

SQLPLUS does access the database.
The TNSListener is up.

Environment

Release: 15.5 MP2

Component: Oracle 12.2.0.1 Enterprise in a two server grid

Resolution

1. Stop the Enforce services.
2. Shut down the DLP database.
3. Reboot the Oracle servers.
4. Ensure the DLP database is up and running.
5. Reboot the Enforce server. You may only need to restart the Enforce services.

It appears as if Oracle was not able to access the TNSListener after the patch was applied.