The password does not meet the password policy requirements, just follow these steps to Disable Password complexity in Windows Server 2012
1. In the Server Manager click on Tools and from the drop down click Group Policy Management
2. Expand Forrest >> Domains >> Your Domain Controller.
3. Right click on the Default Domain Policy and click on the Edit from the context menu.
4. Now Expand Computer Configuration -> Policies -> Windows Settings -> Security Settings -> Account Policies -> Password Policy
5. Double-click on the Passwords Must Meet Complexity Requirements option in the right pane.
6. Select Disabled under define this policy setting:
7. Click Apply then OK all the way out and close the GPO window.
8. In order to refresh the policy type the following command: “gpupdate /force” in the CMD window and click ENTER.