Welcome to our Support Community! I'm sorry your parents continue to receive error messages when trying to view their online account. The tickets shouldn't have been closed without following up with you. I took a look at the tickets and both of them are requesting more specific information. My recommendation is to work with T-Force over Facebook or Twitter and share the ticket numbers with them. They'll be able to update the tickets with the remaining info so hopefully you'll get some answers. One thing I do know for sure is that the app will not function properly for their accounts as they're prepaid. We're currently working on our prepaid app, however, the online experience shouldn't be giving you this error message.
Switching browsers worked for me. With another computer and laptop I wound up with 3 sources to access the site. On my windows 10 laptop Microsoft Edge works,