How can I switch one the 'Maintenance' (read-only) option in Confluence 6.10.0

I just installed trial version of Confluence 6.10.0, also to test the new read only functionality. But the ‘Maintenance’-Button doesn’t appear in General Configuration.

Do you have a valid Data Center license installed? Read only mode is only for Data Center licensed instances.

I didn’t see… It is only for data center :frowning: Sorry.