I am also receiving reports of this error from users, however I have not been able to replicate the error on my browsers. A few users are reporting that the Experience Builder application is not loading at all. I have advised to clear the site or browser cache and this seemed to work for a few users, but not for all users. I am unable to share the app as it is not shared with everyone/public. Wish I could share more info, but the user does not seem particularly savvy with technology as this is part of a community science project and they are a volunteer. That also means that since the user is using their personal computer/browser, the settings are not controlled.