My alphasmart neo 2 has a data change malfunction!

My Neo has had a malfunction saying a data change occurred and asking if I replaced the lithium backup battery. My Neo has had this same malfunction three times now, which is why I don't believe it's the battery. There obviously isn't a producer anymore, so is their any way to fix it?

Could it still be the lithium backup battery after this has happened multiple times and if it's software, is there anything I can do?