notebook disappeared, any way to retrieve it? Log says "NaN"
I don't know what happened. Suddenly, my whole notebook disappeared. Undo doesn't work. I've been working on it the whole day. :(
Some more details would be really helpful to help diagnose this.
And what is the relevance of log saying "NaN"? Are you running "log" trying to get error message? "log" is the mathematical log function.
In the notebook, there is a "History" tab, perhaps your old versions are there.