I have 11 Landsat 8 bands downloaded from the USGS EarthExplorer website. I am trying to move them to a mosaic dataset so I can use that mosaic dataset for the Build Footprint tool to remove the black rectangle around each band. I tried to follow this tutorial on How to add Landsat 7 data to a mosaic dataset but got the yellow exclamation mark error. Don't know what I am doing wrong. Please let me know. Thanks!