Ok, I got this error solved. I needed to use rootpw in my ldif to get over it.
Villem Alari

e-post: villem@ekool.ee
mobiil: +37253939163

Begin forwarded message:

From: Villem Alari <villem@ekool.ee>
Date: 22 august 2007 11:55:45 GMT+03:00
To: openldap-software@openldap.org
Subject: 'simpleSecurityObject' requires attribute 'userPassword'

Entry (cn=admin,dc=example,dc=com): object class 'simpleSecurityObject' requires attribute 'userPassword'
slapadd: dn="cn=admin,dc=example,dc=com" (line=12): (65) object class 'simpleSecurityObject' requires attribute 'userPassword'

Why does it say that 'simpleSecurityObject' requires attribute 'userPassword'. What password it means? I have done everything exactly as it is said here till the point where it says add the new content sudo slapadd -l init.ldif. After doing that this 'userPassword' appeared.

Regards,
Villem Alari