Fatal Error: The Process Does Not Possess The SeSecurityPrivilege – WSUS

After installing WSUS, you get this fatal error when running post installation tasks:

Fatal Error: The process does not possess the ‘SeSecurityPrivilege’ privilege which is required for this operation.

This fatal error is caused by a lack of permissions and ‘SeSecurityPrivilege’ refers to the <I>Log on as a service</I> permission granted in the Local Security Policy.

To fix this, edit the Local Security Policy- > Local Policies -> User Rights Assignment and add the appropriate account (which is some weirdly named local account – I’m sorry, I cba to work out which one. I fixed my issue by taking my PC out of the GPO that was applying local security policy rights).