Open Session PLEASE HELP!

I have a DVD-R with an open session and 1KB (!!!) written on it… It says i can’t use Disck-at-once to add any files but it doesn’t give me a choice of Track-at-once.
Is there any chance I might be able to use this DVD-R and add files to it, or it’s done and it’s useless now?

Are you doing multisession? How did you write the 1k?