It always gives an ajax error. This has been the same problem over and over. Seems like it didn't start happening till after the support expired so you have to renew the support just to get your question answered to fix the issue. Other people in the forum also have issues with this error. You can google "An error occurred loading saving the form" and a bunch of people with the same message has the same issue but the author says he has never encountered the error. Even in the support queue instead of helping he just be like "send me login details" so other people with the same issue can't even look at what other people have done to fix the issue because he never says. He could easily be like "if you see ajax error try this and that and if the problem persists, send me an email" but he doesn't cause he wants you to renew support to fix an issue that keeps happening after every plugin update. I have two licenses of this plugin for two different clients and it is the same thing on both websites.