I'm trying to upload photos to my carousel and every time I try to upload a photo and click add it gives me an X in the box where the picture should be.
This is an issue, where the way the file is saved affects its ability to be uploaded. Open the photo in paint and re-save with a slightly different name and file type (.png to .jpg or vice/versa). Also note that if the file type is saved in capital letters (.PNG or .JPG/JPEG) this may be the cause of the issue also. Once done re-saving, trying again should provide no issue with the photo upload.