Our system can generate thumbnails for files up to 250MB, depending on how the file is structured. When a file has a large number of layers or high resolution, it’s possible our system will fail to generate a thumbnail.
If your file didn’t get a preview image; you can upload a thumbnail to the file. Simply create a smaller version of the image in .png format and upload the thumbnail by clicking on the image. Now, find “Thumbnail” in the menu to the right, and click on the pencil icon and select “upload thumbnail” – this will add a small preview of the image in the grid. The recommended size is 500px width.