After selecting the csv file and getting the screen to map a few differently named fields, the buttons in the selection window are below the view and cannot be seen, so I can't enter the selections, thus not being able to finish the challenge.  I've experienced this when actually using the import wizard (versus for Trailhead), too.  It seems to happen randomly and corrects itself randomly.  Thoughts or suggestions?

After selecting the csv file and getting the screen to map a few differently named fields, the buttons in the selection window are below the view and cannot be seen, so I can't enter the selections, thus not being able to finish the challenge.  I've experienced this when actually using the import wizard (versus for Trailhead), too.  It seems to happen randomly and corrects itself randomly.  Thoughts or suggestions?

I am facing  problem During Completion of Trailhead Challenge ,Suddenly  "Check Challenge" button is not showing .In Developer Edition I am alredy loged in