When the third mobile phone of Nokia S60 opens the SMS, it prompts: System error (-20), why?

Equivalent to losing computer system files, try the following methods:

1\ Removed the memory card. If it is normal, there is something wrong with the card. Format the memory card.

2\ Soft mobile phone, *#7370#, default password 12345, pay attention to backup the data in the mobile phone first. After the completion of the mobile phone, it is blank, just like a new one.