I have a problem in the parsys: for example, in my sidebar, in preview or disabled mode, the wrapper (cq:htmlTag) of the first component is not closed, so it wrap also other components and it brokes my html.
Please provide more information, Are you referring to custom components in the parsys? Do you see this behavior with OOTB components? If you opened the We Retail sample site and dropped a few OOTB Core components - do you see this issue?
are you sure that nothing else is stopping parsys to render properly? I had the same problem with older version of AEM (6.1 SP1) but it turns out that there is an exception within one of components inside.