I ran into issues uploading multiple imagery raster layers, and would run into issues where the layer would be created, but there would be no underlying data associated. I found out this was due to a character limit which was not made clear when uploading.
To fix this, it would be nice to see a prompt that warns you when you have reached the character limit, and to suggest a new naming convention. Additionally, the files that cause the error should be flagged, and the remaining files should continue to upload without malfunctioning.