issues when uploading to lightroom

When I try to upload photos from my SD card to Lightroom, I notice that lightroom will start counting down my photos before I even hit ok and by the time I do I get a missage saying I have no photos or videos to dowon load???  It done this a few times now.  I know the card is no corrupt.  And I finally got the photos down loaded from my other card on to Lightroom now I cant seem to get this one.  I have already done this a few days ago to. But can not find the uploads any where, even though I was in the middle of editing them.  Can some one please help me?