Yeah, that’s not good that the “Preview” isn’t working properly. I think we would need temporary access to your site to track down what is causing the issue. It sounds like it is a conflict somewhere. There may be an error shown in the Developer Tools in Chrome. It’s likely not something that will be hard to track down, but having access will be a huge help.
If you would like for us to take a look, please submit a support ticket with login information.