Symantec Backup Exec 12.5 + Windows Server 2012 R2: V-79-57344-65225 – A failure occurred accessing the Writer metadata.

I have installed Symantec Backup Exec 12.5 agent(Push Installation) in Windows 2012 R2 server. I have followed bellow URL, but each time getting same error while start the job. Please note that Main Backup Exec Server Software is installed in Windows 2003 Server.

https://support.symantec.com/en_US/article.TECH29345.html

I have took bellow steps but same result:

1. Volume Shadow Copy Service already been changed to Manual at 2012 R2 Server.

2. I have checked "vssadmin list writers" in agent pc & VSSADMIN writers shows a "stable" status.

3. System Reserved Partition a drive letter is already been assigned. I have checked it.

Would you like to support me to get the resolution!