The 86000C0A error is caused due to the incorrect permissions on the user object; this is because the user object isn’t inheriting permissions from the parent containers that are required for Exchange ActiveSync.
Steps to Resolve this error-
- Start the Active Directory Users and Computers management tool.
- From the View menu, select Advanced Features.
- Navigate to the user, right-click the user, and select Properties.
- Select the Security tab (if you don’t see Security, the Advanced Features menu item isn’t enabled from step 2).
- Click the Advanced button on the Security tab.
- Ensure that the option Include inheritable permissions from this object’s parent is selected, or, for Windows Server 2012, press the Enable Inheritance button.
Advanced Security Settings with Enable Inheritance Button
- Click OK to all dialog boxes.