Fookin Oracle. I hate it already.

Oracle Product Info: Authentication adapter initialization failed:

When scheduling Jobs or Events through the Enterprise Manager 2.x Console, the Oracle Management Server takes the request from the Console and submits it to the Intelligent Agent on the target server. The Intelligent Agent attempts to establish a 'new' Operating System (OS) logon session for each job that itreceives. The OS logon credentials are pulled from the Console's Preferred Credentials settings. In the Preferred Credentials section, each discovered service is listed along with its service type. For OS logons, the ' NODE ' service type must contain a valid OS user that has the correct permissions.

If the logon information provided to the Intelligent Agent is incorrect or missing, the Intelligent Agent will return the error:

VNI-2015: Authentication Error"

From MS help:

To assign user rights for your local computer
Open Local Security Settings.
In the console tree, click User Rights Assignment.

Security Settings
+-Local Policies
    +-User Rights Assignments

Possible solution:
try this:

please do the first three steps in windows. do step 4 in OEM.

1: create a user login ,such as orajob. This user(orajob) should be created in windows. it's a windows user account.

2: put orajob in ora_dba (not required) group

3: grant orajob the ' log on as a batch job'.
from control panel->administrative tools -> local security policy->local policies-> user right asignment -> select 'log on as a batch', add orajob to it.

4: in your OEM, set database prefered credential, specify orajob as the user to run your jobs for your database.

5: then create your job.

Hope it works.