@sgunhouse
Thanks for your reply. I had tried switching off the tablet. I can't see where the X is on my tablet, unless it's the X to close the app. Anyway, I've uninstalled and reinstalled the app. When I'd originally installed the app, it didn't prompt me to open an account, so I've only lost my favourites. I've opened an account on my phone now, so I'll synchronise phone and tablet, which should avoid future losses!
Thanks again for your reply.

Opera is not working on my Samsung tablet. It is working on my android phone. Should I reinitialise? How do I do this? Thanks in advance.