BruceWayne Hi, This is actually the reverse of a question I asked in July of 2014. Is it possible to use the latest version of the iOS client library, with extremely old versions of the server, in this case 3.6. I looked for system requirements but couldn't find them. We're trying to come up with an upgrade strategy for that accounts for our existing client base. Thanks.
Dario Crivelli Indeed we don't report the compatibility constraints of the client libraries among the System Requirements. You can find them resumed in the changelog entries. I confirm that the latest version of the iOS library requires Server version 6.