Can't save file

[Ojutai]

Basically, I have the same issue as this guy. However, when I try to take the advice of what the administrator said (adding the .sav at the end), it also claims there's an error. Can someone help?
https://gyazo.com/20cdfb7021c45d507bf1314c458ab664

Then, when I go into the battery folder, I do find an SAV file (even though there wasnt one before), and when I press on it, this message displays.

https://gyazo.com/b10cd25c59264deaf8fce69eec4548f4

Then, after pressing ok, another message pops up:

https://gyazo.com/57585bad07d08e228a3698fe45ee0f9b

After all of this, closing desmume and checking the batteries folder AGAIN, there's a new file, except its not sav file (its dsv) and its 381 KB.

Can someone help me? I have the save file loaded on pokegen but I'm afraid to close the pokegen itself since I know that the moment I close the pokegen, all my data is gone (I deleted everything in the batteries folder afterwards to help clean it out)