12c TDE: ORA-46624: cannot find the source keystore

I'm new to 12c TDE and trying to setup an environment for testing encryption.

I have two 12c databases on a single physical server (win 2k8 r2). I implemented basic TDE for DB1 with no errors, but get the above error while implementing in DB2 when setting the key using tag...

My steps used IN DB1: (no errors occurred )

1. Appended the below in sqlnet.ora

ENCRYPTION_WALLET_LOCATION=

  (SOURCE=

  (METHOD=FILE)

  (METHOD_DATA=

  (DIRECTORY=E:\oracle\product\12.1.0\wallets\%oracle_sid%)))

2. Create a key mgr db account and granted the below

GRANT  ADMINISTER KEY MANAGEMENT to KEYMGR;

GRANT  SYSKM to KEYMGR;