Save to web error for photoshop elements 15

I created a gif that I am trying to save to web but I keep getting the error - The operation could not be completed. the original gif I made was 1280px by 720px. then I tried a smaller one of 775px by 500px and still got the same error. Can someone please assist this newbie. I had photoshop for 3years and just recently started exploring it more and now I ran into this problem and it put my project on hold.