Okay, I figured it out. I had to disconnect the USB and exit MS (I came back a few hours later after the tablet went to sleep). When I connected again I could see the file. I think I might originally have exported the file (within the tablet) while the tablet was connected to the computer. So, I guess I had to "reset" the usb connection so it could see the file (or something like that).
By the way, I can't help suspecting that the loading problem that caused me to lose all my data had to with my hard shut off the tablet. I mean, when you exit MS, you don't really "quit" the program. And when you shut off the tablet, it is not saving anything. So I suspect, that the hard shut off of the tablet (holding the power button down for 3 seconds, etc.) is related to this problem. Maybe if there was a way to shut down mobilesheets (sort of how you exit from a word processing program in Windows) this would resolve the issue? [I know I am talking with very little knowledge about programming in the Android OS, etc., but I figured it couldn't hurt to let you know what I was thinking). Anyway, thanks for your continued responsiveness, Mike.
By the way, I can't help suspecting that the loading problem that caused me to lose all my data had to with my hard shut off the tablet. I mean, when you exit MS, you don't really "quit" the program. And when you shut off the tablet, it is not saving anything. So I suspect, that the hard shut off of the tablet (holding the power button down for 3 seconds, etc.) is related to this problem. Maybe if there was a way to shut down mobilesheets (sort of how you exit from a word processing program in Windows) this would resolve the issue? [I know I am talking with very little knowledge about programming in the Android OS, etc., but I figured it couldn't hurt to let you know what I was thinking). Anyway, thanks for your continued responsiveness, Mike.