On the Windows 10 app, I recorded a lot of data and then saved to a csv file, which was created OK. However, when I later went back to look at the log file I found it to have zero size and was empty. On a second attempt following the same steps with the same amount of data (about 10 minutes worth), the file was created successfully. So I don't know how to reproduce the problem.
(BTW, maybe this thread could be pinned like the other 121GW threads? I had to scroll down quite a bit to find it.)