Hello,
I just got an old Ace GT5830 from someone. Yesterday I had the same problem, when trying to switch to my home network there would only be a message "Error". Nothing, not a hint. Not a single network visible and no option to press or check. But then surprise, my phone said I need to charge it. It then connected to my network without any issues. I hope this helps a few people, possibly when the battery is too low Android does not let you connect.
Regards,
Pete