I recently downloaded Krita and as I began working on my first drawing, my pen quits halfway through. I've restarted the application a few times and checked if anything was selected, but nothing works! It's incredibly frustrating and I can't seem to find any solutions... Please help!

I had the same problem.In the wireless default settings was set at two minutes to turn the pen off after changing the values to five minutes all was good.If your using windows ,from memory after the Tablet went to sleep Windows would disconnect the pen drivers. I mainly use the USB to connect to my Tablet.Krista has tutorials on setting up tour Tablet.Helped me heaps.Hope this helps