I imported files into organizer and did view them. However, I must have done something wrong because I now can not either view or import files in organizer. Any help will be appreciated.
Take a look at the View menu. You may have turned off the view of Media>Photos by using the keyboard shortcut Ctrl+1 (on Windows). Try pressing Ctrl+1 again to toggle the photo view back on. Ctrl+2 toggles the video files on and off.
Or you may have a filter in place. Please give us a screenshot of your Organizer window if my above tip does not work.
And please explain in more detail why you can't import files into the organizer. What method are you using and what happens when you try to import the photos?