gif keeps exporting as still image
Hello,
I have made the frames for a gif on Photoshop( its the CC 2017 version) and I can save it, however when I try to export it the 'animation' box on 'save for web' is greyed out:

and when I click preview this still image comes up;

I just cant seem to export it successfully, any help would be much appreciated!
Thank you ![]()
