Latest questions about "data file"

I have Q and E 4. I open it as usual but there is no data. Where is the data file? Can't see where it is located.

PiFile doesn't work: "The data File is created by PIFile v 2.x and is not supported" I work with v4 and my datafile is in v4. Last week it worked very well, today it gives errors.

Is it possible to produce a complete data file with the software? Whats values are replaced by SRCware? If yes, how to create it (and identify it)?