Hello,

Here are the Knowledgebase Articles available for SEP 12.1.2015 (RU2) which would assist you to prepare for this Latest Release.

NOTE: This Article would be updated as and when new Articles in reference to SEP 12.1.2015 (RU2) gets published.

Product Guides

Symantec™ Endpoint Protection and Symantec Network Access Control 12.1.2 Installation and Administration Guide

https://www.symantec.com/business/support/index?page=content&id=DOC6153

Symantec™ Endpoint Protection and Symantec Network Access Control 12.1.2 Client Guide

https://www.symantec.com/business/support/index?page=content&id=DOC3719

About Symantec Endpoint Protection 12.1.2 product guide locations

http://www.symantec.com/docs/HOWTO81153

Installation and Getting Started.

Symantec™ Endpoint Protection 12.1.2 Getting Started Guide

http://www.symantec.com/docs/DOC4322

What's new in Symantec Endpoint Protection 12.1.2

http://www.symantec.com/docs/HOWTO81091

System Requirements for Symantec Endpoint Protection, Enterprise and Small Business Editions, and Network Access Control 12.1.2

http://www.symantec.com/docs/TECH195325

Symantec Endpoint Protection for Macintosh Frequently Asked Questions

http://www.symantec.com/docs/TECH134203

Supported upgrade paths for Symantec Endpoint Protection Manager

http://www.symantec.com/docs/HOWTO81069

Supported upgrade paths for the Symantec Endpoint Protection client

http://www.symantec.com/docs/HOWTO81070

Upgrading or migrating to Symantec Endpoint Protection 12.1.2 (RU2)

http://www.symantec.com/docs/TECH197426

Best practices for upgrading to Symantec Endpoint Protection 12.1.2

http://www.symantec.com/docs/TECH163700

Migrating from Symantec AntiVirus or Symantec Client Security to Symantec Endpoint Protection 12.1 or later

http://www.symantec.com/docs/HOWTO80791

Upgrading to a new release of Symantec Endpoint Protection

http://www.symantec.com/docs/HOWTO80759

Best practices for virtualization with Symantec Endpoint Protection 12.1.2

http://www.symantec.com/docs/TECH197344

Symantec Endpoint Protection Manager 12.1.2 Database Schema

http://www.symantec.com/docs/DOC6039

About the types of Group Update Providers 

http://www.symantec.com/docs/HOWTO80957

Third-party security software removal support in Symantec Endpoint Protection 12.1 RU2

http://www.symantec.com/docs/TECH195029

How to's

Why do I need to replace the client-server communications file on the client computer?

http://www.symantec.com/docs/HOWTO81261

Restoring client-server communications by using a client installation package

http://www.symantec.com/docs/HOWTO81455

Managing the client-server connection

http://www.symantec.com/docs/HOWTO81337

What is the processing order of an Explicit GUP list within version 12.1.2 of Symantec Endpoint Protection?

http://www.symantec.com/docs/TECH196741

Troubleshooting

Error messages appear when installing Symantec Endpoint Protection 12.1.2 on Windows 2000

http://www.symantec.com/docs/TECH196257

After upgrading to version 12.1.2 of the Symantec Endpoint Protection Manager, an error is displayed when trying to launch the SEPM's Java remote console

http://www.symantec.com/docs/TECH198977

Creating a network scan password with SHA-256 hashing after upgrading to Symantec Endpoint Protection 12.1.2

http://www.symantec.com/docs/TECH194754

The Symantec Endpoint Protection (SEP) 12.1.2 Host-Integrity Custom Requirement for Checking Symantec Antivirus-Infected is Not Backwards Compatible to Previous Versions

http://www.symantec.com/docs/TECH196253

Compatibility between Symantec Endpoint Protection/Symantec AntiVirus for Macintosh and HFS Extended, case-sensitive formatted volumes

http://www.symantec.com/docs/TECH104314

Navigation to the next page of the Audit report saved from the Symantec Endpoint Protection Manager shows the error "A Runtime Error has occured. Line:9579 Error:Object expected"

http://www.symantec.com/docs/TECH195152

NOTE: You could also search on the Symantec Knowledgebase as well -

http://www.symantec.com/business/support/index?page=content&key=54619&channel=TECHNICAL_SOLUTION

Hope that helps!!