OpenLDAP credentials issue
At the "Populating LDAP" stage I was getting 'credentials (49)' errors.
All previous activities seemed to work just fine, but not that.
I eventually found that it worked if I first did:
sudo su openldap
I'm not sure whether I just found a way around another problem, or whether this was an expected action before ldap administration.
It took me a while to find that because until then all seemed fine. It asked for passwords as expected, ans seemed to do actions as expected.