Cannot update Post

Could you let me know what happens when you try to update a post? Do you get an error? If so, which one?

If you don’t get any errors, but clicking on the Update button doesn’t do anything, could you check for Javascript errors on the editor page when Jetpack is active, as explained here:
http://codex.ww.wp.xz.cn/Using_Your_Browser_to_Diagnose_JavaScript_Errors

Let me know what you find!