I have high resolution (30m) LULC map tiles (from globallandcover.com) covering quite a large area but after mosaicking to a new raster I get huge gaps between the tiles. I tried to remove black edges from mosaicked .tif LULC using "Build footprints" in ArcMap, however when I try to add mosaicked LULC raster it says "One or more dropped items were invalid and will not be added to the control". How can I solve this issue? 