Thank you for you answer. The problem is with the interpretation of the specification. Some client implementation consider the control must have an empty value (Microsoft implementation) instead of a "null" value
I opened the ticket ITS#10195 to describe that. There was an old ticket ITS#7298, that ask to change the implementation from an empty value to a null value. I think, the best would be to have an implementation that accept both empty or null value for this control. I hope that this approach will be adopted by openldap team.
